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  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  <P align="center" style="font-size: 10pt"><B>As filed with the Securities and Exchange Commission on November&nbsp;2, 2004</B>
  
  
  
  <DIV align="right" style="font-size: 10pt"><B>Registration
  No.&nbsp;333-</B>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</DIV>
  
  
  
  <HR size="4" noshade color="#000000" style="margin-top: -5px">
  <HR size="1" noshade color="#000000" style="margin-top: -10px">
  
  
  
  
  
  
  
  
  
  <P align="center" style="font-size: 14pt"><B>UNITED STATES<BR>
  SECURITIES AND EXCHANGE COMMISSION</B>
  <DIV align="center" style="font-size: 12pt"><B>Washington, D.C.
  20549</B></DIV>
  <DIV align="center" style="font-size: 10pt"><HR size="1" noshade width="25%" align="center"></DIV>
  
  <P align="center" style="font-size: 18pt"><B>FORM S-8</B>
  
  <DIV align="center" style="font-size: 12pt"><B>REGISTRATION
  STATEMENT<BR>
  UNDER<BR>
  THE SECURITIES ACT OF 1933</B></DIV>
  <P align="center" style="font-size: 10pt"><HR size="1" noshade width="25%" align="center">
  
  <P align="center" style="font-size: 24pt"><B>Art Technology Group, Inc.</B>
  
  
  <DIV align="center" style="font-size: 10pt">(Exact name of registrant
  as specified in its charter)</DIV>
  
  
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="60%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="19%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="20%">&nbsp;</TD>
  </TR>
  
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>Delaware</B>
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD colspan="3" align="center" valign="top"><B>04-3141918</B></TD>
  </TR>
  
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(State or other jurisdiction of incorporation or organization)
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD nowrap colspan="3" align="center" valign="top">(I.R.S. employer identification no.)
  </TD>
  </TR>
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>25 First Street, Second Floor, Cambridge, Massachusetts</B>
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="top"><B>02141</B></TD>
      <TD nowrap valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">(Address of principal executive offices)
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD nowrap colspan="3" align="center" valign="top">(Zip code)
  </TD>
  </TR>
  
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
  <P align="center" style="font-size: 10pt"><B>Primus 1999 Non-officer Stock Option Plan</B>
  
  
  <DIV align="center" style="font-size: 10pt"><B>Primus 1999 Stock Incentive Compensation Plan</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt">(Full title of the plan)</DIV>
  
  <P>
  <DIV align="center" style="font-size: 10pt"><HR size="1" noshade width="25%" align="center"></DIV>
  
  <P>
  <DIV align="center" style="font-size: 10pt"><B>Robert D. Burke</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt"><B>President and Chief Executive Officer</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt"><B>Art Technology Group, Inc.</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt"><B>25 First Street, Second Floor</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt"><B>Cambridge, Massachusetts 02141</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt">(Name and address of agent for service)</DIV>
  
  <P>
  <DIV align="center" style="font-size: 10pt"><B>(617)&nbsp;386-1000</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt">(Telephone number,
  including area code, of agent for service)<BR><BR>
  <HR size="1" noshade width="25%" align="center"></DIV>
  
  
  <DIV align="center" style="font-size: 10pt"><B>WITH COPIES TO:</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt"><B>John D. Patterson, Jr.</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt"><B>Robert W. Sweet, Jr.</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt"><B>Foley Hoag LLP</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt"><B>155 Seaport Boulevard</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt"><B>Boston, Massachusetts 02210</B></DIV>
  
  
  <DIV align="center" style="font-size: 10pt"><B>(617)&nbsp;832-1000</B>
  <P>
  <HR size="1" noshade width="25%" align="center"></DIV>
  
  
  
  <P align="center" style="font-size: 10pt"><B>CALCULATION OF REGISTRATION FEE</B>
  
  
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="33%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="8%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="9%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="7%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="7%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="center"><B>Title of</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>Amount</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>Proposed maximum</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>Proposed maximum</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>Amount of</B></TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="center"><B>securities to be</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>to be</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>offering price</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>aggregate</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>registration</B></TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="center"><B>registered</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>registered</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>per share</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>offering price</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>fee</B><HR size="1" noshade></TD>
  </TR>
  
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD><DIV style="margin-left:10px; text-indent:-10px">Common stock, $0.01
  par value (1)</DIV></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right">&nbsp;</TD>
      <TD align="right">1,178,174 </TD>
      <TD nowrap>(2)</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right">$</TD>
      <TD align="right">0.70</TD>
      <TD nowrap>(3)</TD>
      <TD>&nbsp;</TD>
      <TD align="right">$</TD>
      <TD align="right">824,722</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right">$</TD>
      <TD align="right">105</TD>
      <TD>&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD><DIV style="margin-left:10px; text-indent:-10px">Common stock, $0.01
  par value (1)</DIV></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right">&nbsp;</TD>
      <TD align="right">2,052,006 </TD>
      <TD nowrap>(4)</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right">$</TD>
      <TD align="right">0.65</TD>
      <TD nowrap>(3)</TD>
      <TD>&nbsp;</TD>
      <TD align="right">$</TD>
      <TD align="right">1,333,804</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right">$</TD>
      <TD align="right">169</TD>
      <TD>&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD><DIV style="margin-left:10px; text-indent:-10px">Common stock, $0.01
  par value (1)</DIV></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right">&nbsp;</TD>
      <TD align="right">2,795,468 </TD>
      <TD nowrap>(5)</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right">$</TD>
      <TD align="right">0.88</TD>
      <TD nowrap>(6)</TD>
      <TD>&nbsp;</TD>
      <TD align="right">$</TD>
      <TD align="right">2,460,012</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right">$</TD>
      <TD align="right">312</TD>
      <TD>&nbsp;</TD>
  </TR>
  
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD><DIV style="margin-left:20px; text-indent:-10px">Total</DIV></TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right">$</TD>
      <TD align="right">586</TD>
      <TD>&nbsp;</TD>
  </TR>
  
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
  
  <P>
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="1%" nowrap align="right">(1)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>Each share includes one right to purchase shares of ATG&#146;s series A
  junior participating preferred stock pursuant to the terms of ATG&#146;s rights
  agreement dated September&nbsp;26, 2001.</TD>
  </TR>
  
  </TABLE>
  
  
  <P>
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="1%" nowrap align="right">(2)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>Represents shares issuable pursuant to stock options outstanding under
  the Primus 1999 Non-officer Stock Option Plan.</TD>
  </TR>
  
  </TABLE>
  
  
  <P>
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="1%" nowrap align="right">(3)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>Calculated pursuant to Rule&nbsp;457(h)(1) under the Securities Act of 1933
  based on the weighted average exercise price per share of the options
  outstanding under each of the stock option plans.</TD>
  </TR>
  
  </TABLE>
  
  
  <P>
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="1%" nowrap align="right">(4)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>Represents shares issuable pursuant to stock options outstanding under
  the Primus 1999 Stock Incentive Compensation Plan.</TD>
  </TR>
  
  </TABLE>
  
  
  <P>
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="1%" nowrap align="right">(5)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>Represents shares of common stock issuable upon exercise of the maximum
  number of stock options available for grant pursuant to the terms of the
  Primus 1999 Stock Incentive Compensation Plan.</TD>
  </TR>
  
  </TABLE>
  
  
  <P>
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="1%" nowrap align="right">(6)</TD>
      <TD width="1%">&nbsp;</TD>
      <TD>Calculated pursuant to Rules 457(c) and (h)(1) under the Securities Act
  of 1933 based on the average of the high and low sale prices of the common
  stock as reported on the Nasdaq National Market on October&nbsp;27, 2004.</TD>
  </TR>
  
  </TABLE>
  
  
  <P>
  <HR size="1" noshade color="#000000" style="margin-top: -2px">
  <HR size="4" noshade color="#000000" style="margin-top: -10px">
  
  
  
  
  
  
  
  
  <P align="center" style="font-size: 10pt">
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  
  
  <!-- TOC -->
  <A name="toc"><DIV align="CENTER" style="page-break-before:always"><U><B>TABLE OF CONTENTS</B></U></DIV></A>
  
  <P><CENTER>
  <TABLE border="0" width="90%" cellpadding="0" cellspacing="0">
  <TR>
  	<TD width="3%"></TD>
  	<TD width="3%"></TD>
  	<TD width="3%"></TD>
  	<TD width="3%"></TD>
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  	<TD width="3%"></TD>
  	<TD width="3%"></TD>
  	<TD width="76%"></TD>
  </TR>
  <TR><TD colspan="9"><A HREF="#000">PART II</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#001">Item&nbsp;3. Incorporation of Documents by Reference</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#002">Item&nbsp;4. Description of Securities</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#003">Item&nbsp;5. Interests of Named Experts and Counsel</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#004">Item&nbsp;6. Indemnification of Directors and Officers</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#005">Item&nbsp;7. Exemption from Registration Claimed</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#006">Item&nbsp;8. Exhibits</A></TD></TR>
  <TR><TD></TD><TD colspan="8"><A HREF="#007">Item&nbsp;9. Undertakings</A></TD></TR>
  <TR><TD colspan="9"><A HREF="#008">SIGNATURES</A></TD></TR>
  <TR><TD colspan="9"><A HREF="#009">EXHIBIT INDEX</A></TD></TR>
  <TR><TD colspan="9"><A HREF="b52327atexv5w1.htm">Ex-5.1 Legal Opinion of Foley Hoag LLP</A></TD></TR>
  <TR><TD colspan="9"><A HREF="b52327atexv23w1.htm">Ex-23.1 Consent of Ernst & Young LLP</A></TD></TR>
  <TR><TD colspan="9"><A HREF="b52327atexv23w2.htm">Ex-23.2 Notice Re: Consent of Arthur Andersen LLP</A></TD></TR>
  </TABLE>
  </CENTER>
  <!-- /TOC -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  
  <!-- link1 "PART II" -->
  <DIV align="left"><A NAME="000"></A></DIV>
  <P align="center" style="font-size: 10pt"><B>PART II</B>
  
  
  <P align="center" style="font-size: 10pt"><B>INFORMATION REQUIRED IN THE REGISTRATION STATEMENT</B>
  
  
  <!-- link2 "Item&nbsp;3. Incorporation of Documents by Reference" -->
  <DIV align="left"><A NAME="001"></A></DIV>
  <P align="left" style="font-size: 10pt"><B>Item&nbsp;3. Incorporation of Documents by Reference.</B>
  
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The following documents, which we filed with the Securities and Exchange
  Commission, are incorporated by reference in this registration statement:
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;our annual report on Form 10-K for the year ended December&nbsp;31, 2003,
  as amended by amendment no. 1 on Form 10-K/ A;
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;our quarterly report on Form 10-Q for the quarter ended March&nbsp;31,
  2004;
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;our quarterly report on Form 10-Q for the quarter ended June&nbsp;30, 2004;
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d)&nbsp;our current report on Form 8-K filed on August&nbsp;11, 2004;
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e)&nbsp;our current report on Form 8-K filed on August&nbsp;18, 2004;
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(f)&nbsp;our current report on Form 8-K filed on September&nbsp;28, 2004;
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(g)&nbsp;our current reports on Form 8-K filed on October&nbsp;12, 2004;
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(h)&nbsp;our current reports on Form 8-K filed on October&nbsp;28, 2004;
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i)&nbsp;our current reports on Form 8-K filed on November&nbsp;1, 2004; and
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(j)&nbsp;the description of our common stock and related preferred stock
  purchase rights contained in our registration statement on Form 8-A filed with
  the SEC on July&nbsp;12, 1999, together with amendments and reports filed for the
  purpose of updating that description, including the Form 8-A/A filed with the
  SEC on October&nbsp;2, 2001.
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In addition, all documents subsequently filed by us pursuant to Sections
  13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended,
  prior to the filing of a post-effective amendment which indicates that all
  securities offered have been sold or which deregisters all securities then
  remaining unsold, are deemed to be incorporated by reference into, and to be a
  part of, this registration statement.
  
  
  <P align="center" style="font-size: 10pt">
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  <!-- link2 "Item&nbsp;4. Description of Securities" -->
  <DIV align="left"><A NAME="002"></A></DIV>
  <P align="left" style="font-size: 10pt"><B>Item&nbsp;4. Description of Securities.</B>
  
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Not Applicable.
  
  <!-- link2 "Item&nbsp;5. Interests of Named Experts and Counsel" -->
  <DIV align="left"><A NAME="003"></A></DIV>
  <P align="left" style="font-size: 10pt"><B>Item&nbsp;5. Interests of Named Experts and Counsel.</B>
  
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The validity of the securities we are registering is being passed upon by
  Foley Hoag LLP, Boston, Massachusetts.
  
  <!-- link2 "Item&nbsp;6. Indemnification of Directors and Officers" -->
  <DIV align="left"><A NAME="004"></A></DIV>
  <P align="left" style="font-size: 10pt"><B>Item&nbsp;6. Indemnification of Directors and Officers.</B>
  
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Section&nbsp;102 of the Delaware General Corporation Law allows a corporation
  to eliminate the personal liability of directors of a corporation to the
  corporation or its stockholders for monetary damages for a breach of fiduciary
  duty as a director, except where the director breached his duty of loyalty,
  failed to act in good faith, engaged in intentional misconduct or knowingly
  violated a law, authorized the payment of a dividend or approved a stock
  repurchase in violation of Delaware corporate law or obtained an improper
  personal benefit. The registrant has included such a provision in its charter.
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Section&nbsp;145 of the Delaware General Corporation Law provides that a
  corporation has the power to indemnify a director, officer, employee or agent
  of the corporation and certain other persons serving at the request of the
  corporation in related capacities against amounts paid and expenses incurred in
  connection with an action or proceeding to which such person is or is
  threatened to be made a party by reason of such position, if such person shall
  have acted in good faith and in a manner he or she reasonably believed to be in
  or not opposed to the best interests of the corporation, and, in any criminal
  proceeding, if such person had no reasonable cause to believe his or her
  conduct was unlawful; provided that, in the case of actions brought by or in
  the right of the corporation, no indemnification shall be made with respect to
  any matter as to which such person shall have been adjudged to be liable to the
  corporation unless and only to the extent that the adjudicating court
  determines that such indemnification is proper under the circumstances.
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Article&nbsp;Eighth of the registrant&#146;s charter provides that no director of
  the registrant shall be personally liable for any monetary damages for any
  breach of fiduciary duty as a director, except to the extent that the Delaware
  General Corporation Law prohibits the elimination or limitation of liability of
  directors for breach of fiduciary duty.
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Article&nbsp;Ninth of the registrant&#146;s charter provides that a director or
  officer of the registrant:
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;shall be indemnified by the registrant against all expenses (including
  attorneys&#146; fees), judgments, fines and amounts paid in settlement incurred in
  connection with any litigation or other legal proceeding (other than an action
  by or in the right of the registrant) brought against such person by virtue of
  his or her position as a director or officer of the registrant if such person
  acted in good faith and in a manner he or she reasonably believed to be in, or
  not opposed to, the
  
  
  <P align="center" style="font-size: 10pt">
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  <P align="left" style="font-size: 10pt">best interests of the registrant, and, with respect to any criminal action
  or proceeding, had no reasonable cause to believe his or her conduct was
  unlawful and
  
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;shall be indemnified by the registrant against all expenses (including
  attorneys&#146; fees) and amounts paid in settlement incurred in connection with any
  action by or in the right of the registrant brought against such person by
  virtue of his or her position as a director or officer of the registrant if
  such person acted in good faith and in a manner he or she reasonably believed
  to be in, or not opposed to, the best interests of the registrant, except that
  no indemnification shall be made with respect to any matter as to which such
  person shall have been adjudged to be liable to the registrant, unless a court
  determines that, despite such adjudication but in view of all of the
  circumstances, he or she is entitled to indemnification of such expenses.
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Notwithstanding the foregoing, to the extent that a director or officer
  has been successful, on the merits or otherwise, including the dismissal of an
  action without prejudice, such person is required to be indemnified by the
  registrant against all expenses (including attorneys&#146; fees) incurred in
  connection therewith. Expenses shall be advanced to a director or officer at
  his or her request, provided that such person undertakes to repay the amount
  advanced if it is ultimately determined that he or she is not entitled to
  indemnification for such expenses.
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Indemnification is required to be made unless the registrant determines
  that the applicable standard of conduct required for indemnification has not
  been met. In the event of a determination by the registrant that the director
  or officer did not meet the applicable standard of conduct required for
  indemnification, or if the registrant fails to make an indemnification payment
  within 60&nbsp;days after such payment is claimed by such person, such person is
  permitted to petition the court to make an independent determination as to
  whether such person is entitled to indemnification. As a condition precedent to
  the right of indemnification, the director or officer must give the registrant
  notice of the action for which indemnity is sought and the registrant has the
  right to participate in such action or assume the defense thereof.
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Article&nbsp;Ninth of the registrant&#146;s charter further provides that the
  indemnification provided therein is not exclusive, and provides that in the
  event that the Delaware General Corporation Law is amended to expand the
  indemnification permitted to directors or officers the registrant must
  indemnify those persons to the fullest extent permitted by such law as so
  amended.
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The indemnification provisions contained in our charter and by-laws are
  not exclusive of any other rights to which a person may be entitled by law,
  agreement, vote of stockholders or disinterested directors, or otherwise. In
  addition, we maintain insurance on behalf of our directors and officers
  insuring them against liabilities asserted against them in their capacities as
  directors or officers or arising out of such statuses.
  
  <!-- link2 "Item&nbsp;7. Exemption from Registration Claimed" -->
  <DIV align="left"><A NAME="005"></A></DIV>
  <P align="left" style="font-size: 10pt"><B>Item&nbsp;7. Exemption from Registration Claimed.</B>
  
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Not Applicable.
  
  
  
  <P align="center" style="font-size: 10pt">
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  
  
  <!-- link2 "Item&nbsp;8. Exhibits" -->
  <DIV align="left"><A NAME="006"></A></DIV>
  <P align="left" style="font-size: 10pt"><B>Item&nbsp;8. Exhibits.</B>
  
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The following exhibits are included as part of this registration
  statement.
  
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="8%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="39%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="3%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="4%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="8%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD colspan="7" nowrap align="center"><B>Incorporated by reference</B><HR size="1" noshade></TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Filed with this</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>&nbsp;</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>&nbsp;</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="left"><B>Exhibit Number</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Description</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Form S-8</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Form</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Filing date with SEC</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>Exhibit number</B><HR size="1" noshade></TD>
  </TR>
  
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.1
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Amended and Restated Certificate
  of Incorporation of Art
  Technology Group, Inc.
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right" valign="bottom">S-8
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">June&nbsp;12, 2003
  </TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="left" valign="bottom">4.1
  </TD>
      <TD nowrap valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">
  4.2
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">
  Amended and Restated By-Laws of
  Art Technology Group, Inc.
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right" valign="bottom">
  S-3
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">July&nbsp;6, 2001
  </TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="left" valign="bottom">
  4.2</TD>
      <TD nowrap valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.3
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">Specimen common stock certificate
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right" nowrap valign="bottom">S-1/A
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">July&nbsp;13, 1999
  </TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="left" valign="bottom">4</TD>
      <TD nowrap valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.4
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">Rights Agreement dated September
  26, 2001 between Art Technology
  Group, Inc. and EquiServe Trust
  Company, N.A., as rights agent
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right" valign="bottom">8-K
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" nowrap valign="bottom">October&nbsp;2, 2001
  </TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="left" valign="bottom">4.1</TD>
      <TD nowrap valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">5.1
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Legal opinion of Foley Hoag LLP
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">X</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="top">&nbsp;</TD>
      <TD valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.1
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Consent of Ernst &#038; Young LLP
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">X</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="top">&nbsp;</TD>
      <TD valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.2
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Notice Regarding Consent of
  Arthur Andersen LLP
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">X</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="top">&nbsp;</TD>
      <TD valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.3
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Consent of Foley Hoag LLP
  (contained in Exhibit&nbsp;5.1)
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">X</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="top">&nbsp;</TD>
      <TD valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">24.1
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Power of Attorney (included on
  the signature page of this
  registration statement)
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">X</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="top">&nbsp;</TD>
      <TD valign="top">&nbsp;</TD>
  </TR>
  
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  <!-- link2 "Item&nbsp;9. Undertakings" -->
  <DIV align="left"><A NAME="007"></A></DIV>
  <P align="left" style="font-size: 10pt"><B>Item&nbsp;9. Undertakings.</B>
  
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;The undersigned registrant hereby undertakes:
  
  
  <P align="left" style="margin-left: 12%; text-indent: -8%; margin-right: 0%; font-size: 10pt">(1)&nbsp;To file, during any period in which offers or sales are being
  made, a post-effective amendment to this registration statement:
  
  
  
  <P align="left" style="margin-left:6%; font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i) To include any prospectus required by Section&nbsp;10(a)(3) of
  the Securities Act;
  
  
  
  <P align="left" style="margin-left:6%; font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii) To reflect in the prospectus any facts or events arising
  after the effective date of the registration statement (or the most
  recent post-effective amendment thereof) which, individually or in
  the aggregate, represent a fundamental change in the information
  set forth in the registration statement. Notwithstanding the
  foregoing, any increase or decrease in volume of securities offered
  (if the total dollar value of securities offered would not exceed
  that which was registered) and any deviation from the low or high
  end of the estimated maximum offering range may be reflected in the
  form of prospectus filed with the Commission pursuant to Rule
  424(b) if, in the aggregate, the changes in volume and price
  represent no more than a 20% change in the maximum aggregate
  offering price set forth in the &#147;Calculation of Registration Fee&#148;
  table in the effective registration statement; and
  
  
  <P align="center" style="font-size: 10pt">
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  <P align="left" style="margin-left:9%; font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(iii) To include any material information with respect to the
  plan of distribution not previously disclosed in the registration
  statement or any material change to such information in the
  registration statement;
  
  
  <P>
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="4%" nowrap align="right">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD><I>provided, however</I>, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply
  if the information required to be included in a post-effective amendment
  by those paragraphs is contained in periodic reports filed with or
  furnished to the Commission by the registrant pursuant to Section&nbsp;13 or
  Section 15(d) of the Exchange Act that are incorporated by reference in
  this registration statement.</TD>
  </TR>
  
  </TABLE>
  
  
  
  <P align="left" style="margin-left:6%; font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) That, for the purpose of determining any liability under the
  Securities Act, each such post-effective amendment shall be deemed to be
  a new registration statement relating to the securities offered therein,
  and the offering of such securities at that time shall be deemed to be
  the initial <I>bona fide </I>offering thereof; and
  
  
  
  <P align="left" style="margin-left:6%; font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(3) To remove from registration by means of post-effective amendment
  any of the securities being registered which remain unsold at the
  termination of the offering.
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;The undersigned registrant hereby undertakes that, for purposes of
  determining any liability under the Securities Act of 1933, each filing of the
  registrant&#146;s annual report pursuant to Section 13(a) or Section 15(d) of the
  Exchange Act that is incorporated by reference in the registration statement
  shall be deemed to be a new registration statement relating to the securities
  offered therein, and the offering of such securities at the time shall be
  deemed to be the initial <I>bona fide </I>offering thereof.
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;Insofar as indemnification for liabilities arising under the
  Securities Act may be permitted to directors, officers and controlling persons
  of the registrant pursuant to the foregoing provisions, or otherwise, the
  registrant has been advised that in the opinion of the Securities and Exchange
  Commission such indemnification is against public policy as expressed in the
  Act and is, therefore, unenforceable. In the event that a claim for
  indemnification against such liabilities (other than the payment by the
  registrant of expenses incurred or paid by a director, officer or controlling
  person of the registrant in the successful defense of any action, suit or
  proceeding) is asserted by such director, officer or controlling person in
  connection with the securities being registered, the registrant will, unless in
  the opinion of its counsel the matter has been settled by controlling
  precedent, submit to a court of appropriate jurisdiction the question whether
  such indemnification by it is against public policy as expressed in the Act and
  will be governed by the final adjudication of such issue.
  
  
  <P>
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  
  </TABLE>
  
  <P align="center" style="font-size: 10pt">
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  
  <P><TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  
  
  </TABLE>
  
  <!-- link1 "SIGNATURES" -->
  <DIV align="left"><A NAME="008"></A></DIV>
  <P align="center" style="font-size: 10pt"><B>SIGNATURES</B>
  
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant to the requirements of the Securities Act of 1933, the registrant
  certifies that it has reasonable grounds to believe that it meets all of the
  requirements for filing on Form S-8 and has duly caused this registration
  statement to be signed on its behalf by the undersigned, thereunto duly
  authorized, in the City of Cambridge, Commonwealth of Massachusetts, on this
  2nd day of November, 2004.
  
  
  <P>
  <TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
  
  <TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
      <TD width="46%" nowrap align="right">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD><B>Art Technology Group, Inc.</B></TD>
  </TR>
  
  </TABLE>
  
  
  <TABLE width="100%" border="0" cellspacing="0" cellpadding="0" style="font-size: 10pt">
  <TR>
      <TD width="48%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="35%">&nbsp;</TD>
      <TD width="15%">&nbsp;</TD>
  </TR>
  <TR>
      <TD>&nbsp;</TD>
      <TD valign="top">By:&nbsp;&nbsp;</TD>
      <TD colspan="2" style="border-bottom: 1px solid #000000">                                  /s/ Robert D. Burke
  &nbsp;</TD>
      <TD>&nbsp;</TD>
  </TR><TR>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD colspan="2">Robert D. Burke&nbsp;</TD>
      <TD>&nbsp;</TD>
  </TR><TR>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD colspan="2">President and Chief Executive Officer&nbsp;</TD>
      <TD>&nbsp;</TD>
  </TR>
  </TABLE>
  
  <P align="center" style="font-size: 10pt"><B>POWER OF ATTORNEY</B>
  
  
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;KNOW ALL BY THESE PRESENTS that each individual whose signature appears
  below hereby constitutes and appoints Robert D. Burke and Edward Terino, and
  each of them, his or her true and lawful attorneys-in-fact and agents with full
  power of substitution, for him or her and in his or her name, place and stead,
  in any and all capacities, to sign any and all amendments (including
  post-effective amendments) to this registration statement, and to file the
  same, with all exhibits thereto, and all documents in connection therewith,
  with the Securities and Exchange Commission, granting unto said
  attorneys-in-fact and agents, and each of them, full power and authority to do
  and perform each and every act and thing which they, or any of them, may deem
  necessary or advisable to be done in connection with this registration
  statement, as fully to all intents and purposes as he or she might or could do
  in person, hereby ratifying and confirming all that said attorneys-in-fact and
  agents or any of them, or any substitute or substitutes for him or her, or any
  or all of them, may lawfully do or cause to be done by virtue hereof.
  
  
  <P align="left" style="font-size: 10pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant to the requirements of the Securities Act, this registration
  statement has been signed by the following persons in the indicated capacities
  as of November&nbsp;2, 2004.
  
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="40%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="59%">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="center"><B>Signature</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Title</B><HR size="1" noshade></TD>
  </TR>
  
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Robert D. Burke
  <HR size="1" noshade width="70%" align="left">
  Robert D. Burke
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">President, Chief Executive Officer and Director
  <I>(Principal Executive Officer)</I></TD>
  </TR>
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Edward Terino<BR>
  <HR size="1" noshade width="70%" align="left">
  Edward Terino
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Senior Vice President, Chief Financial Officer
  <I>(Principal Financial and Accounting Officer)</I></TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Paul G. Shorthose
  <HR size="1" noshade width="70%" align="left">
  Paul G. Shorthose
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Chairman of the Board</TD>
  </TR>
  
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
  
  <P align="center" style="font-size: 10pt">
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="40%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="59%">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="center"><B>Signature</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Title</B><HR size="1" noshade></TD>
  </TR>
  
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ David B. Elsbree
  <HR size="1" noshade width="70%" align="left">
  David B. Elsbree
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Director</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ John R. Held
  <HR size="1" noshade width="70%" align="left">
  John R. Held
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Director</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Ilene H. Lang
  <HR size="1" noshade width="70%" align="left">
  Ilene H. Lang
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Director</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Mary Makela<BR>
  <HR size="1" noshade width="70%" align="left">
  Mary Makela
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Director</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ Phyllis S. Swersky
  <HR size="1" noshade width="70%" align="left">
  Phyllis S. Swersky
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Director<BR>
  </TD>
  </TR>
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">
  <BR>
  <HR size="1" noshade width="70%" align="left">
  Michael A. Brochu
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">
  Director</TD>
  </TR>
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
  
  <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><BR><HR size="1" noshade width="70%" align="left">
  Daniel C. Regis
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Director</TD>
  </TR>
  
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
  
  <P align="center" style="font-size: 10pt">
  </DIV>
  
  <!-- PAGEBREAK -->
  <P><HR noshade><P>
  <H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
  
  <DIV style="font-family: 'Times New Roman',Times,serif">
  
  <!-- link1 "EXHIBIT INDEX" -->
  <DIV align="left"><A NAME="009"></A></DIV>
  <P align="center" style="font-size: 10pt"><B>EXHIBIT INDEX</B>
  
  
  <DIV align="center">
  <TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
  <!-- Begin Table Head -->
  <TR valign="bottom">
      <TD width="8%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="39%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="3%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="4%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="8%">&nbsp;</TD>
      <TD width="5%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
      <TD width="1%">&nbsp;</TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap colspan="7" align="center"><B>Incorporated by reference</B><HR size="1" noshade></TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Filed with this</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>&nbsp;</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>&nbsp;</B></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>&nbsp;</B></TD>
  </TR>
  <TR style="font-size: 8pt" valign="bottom">
      <TD nowrap align="left"><B>Exhibit Number</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Description</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Form S-8</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Form</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center"><B>Filing date with SEC</B><HR size="1" noshade></TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="center" colspan="3"><B>Exhibit number</B><HR size="1" noshade></TD>
  </TR>
  
  <!-- End Table Head -->
  <!-- Begin Table Body -->
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.1
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Amended and Restated Certificate
  of Incorporation of Art
  Technology Group, Inc.
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right" valign="bottom">S-8
  </TD>
      <TD>&nbsp;</TD>
      <TD align="right" valign="bottom">June&nbsp;12, 2003
  </TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="bottom">4.1</TD>
      <TD nowrap valign="top">&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.2
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Amended and Restated By-Laws of
  Art Technology Group, Inc.
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right" valign="bottom">S-3
  </TD>
      <TD>&nbsp;</TD>
      <TD align="right" valign="bottom">July&nbsp;6, 2001
  </TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="bottom">4.2</TD>
      <TD nowrap valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.3
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Specimen common stock certificate
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right" nowrap valign="bottom">S-1/A
  </TD>
      <TD>&nbsp;</TD>
      <TD align="right" valign="bottom">July&nbsp;13, 1999
  </TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="bottom">4</TD>
      <TD nowrap valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">4.4
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Rights Agreement dated September
  26, 2001 between Art Technology
  Group, Inc. and EquiServe Trust
  Company, N.A., as rights agent
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="right" valign="bottom">8-K
  </TD>
      <TD>&nbsp;</TD>
      <TD align="right" nowrap valign="bottom">October&nbsp;2, 2001
  </TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="bottom">4.1</TD>
      <TD nowrap valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">5.1
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Legal opinion of Foley Hoag LLP
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">X</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="top">&nbsp;</TD>
      <TD valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.1
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Consent of Ernst &#038; Young LLP
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">X</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="top">&nbsp;</TD>
      <TD valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.2
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Notice Regarding Consent of
  Arthur Andersen LLP
  
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">X</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="top">&nbsp;</TD>
      <TD valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.3
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Consent of Foley Hoag LLP (contained in Exhibit&nbsp;5.1)
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">X</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="top">&nbsp;</TD>
      <TD valign="top">&nbsp;</TD>
  </TR>
  
  <TR valign="bottom">
      <TD>&nbsp;</TD>
  </TR>
  <TR valign="bottom">
      <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">24.1
  </DIV></TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">Power of Attorney (included on
  the signature page of this
  registration statement)
  </TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="bottom">X</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD align="left" valign="top">&nbsp;</TD>
      <TD>&nbsp;</TD>
      <TD nowrap align="right" valign="top">&nbsp;</TD>
      <TD align="right" valign="top">&nbsp;</TD>
      <TD valign="top">&nbsp;</TD>
  </TR>
  
  <!-- End Table Body -->
  </TABLE>
  </DIV>
  
  
  
  <P align="center" style="font-size: 10pt">
  </DIV>
  
  </BODY>
  </HTML>
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text: sv8
  Table of Contents
  As filed with the Securities and Exchange Commission on November 2, 2004
  Registration
  No. 333-
  UNITED STATES
  SECURITIES AND EXCHANGE COMMISSION
  Washington, D.C.
  20549
  FORM S-8
  REGISTRATION
  STATEMENT
  UNDER
  THE SECURITIES ACT OF 1933
  Art Technology Group, Inc.
  (Exact name of registrant
  as specified in its charter)
  Delaware
  04-3141918
  (State or other jurisdiction of incorporation or organization)
  (I.R.S. employer identification no.)
  25 First Street, Second Floor, Cambridge, Massachusetts
  02141
  (Address of principal executive offices)
  (Zip code)
  Primus 1999 Non-officer Stock Option Plan
  Primus 1999 Stock Incentive Compensation Plan
  (Full title of the plan)
  Robert D. Burke
  President and Chief Executive Officer
  Art Technology Group, Inc.
  25 First Street, Second Floor
  Cambridge, Massachusetts 02141
  (Name and address of agent for service)
  (617) 386-1000
  (Telephone number,
  including area code, of agent for service)
  WITH COPIES TO:
  John D. Patterson, Jr.
  Robert W. Sweet, Jr.
  Foley Hoag LLP
  155 Seaport Boulevard
  Boston, Massachusetts 02210
  (617) 832-1000
  CALCULATION OF REGISTRATION FEE
  Title of
  Amount
  Proposed maximum
  Proposed maximum
  Amount of
  securities to be
  to be
  offering price
  aggregate
  registration
  registered
  registered
  per share
  offering price
  fee
  Common stock, $0.01
  par value (1)
  1,178,174
  (2)
  $
  0.70
  (3)
  $
  824,722
  $
  105
  Common stock, $0.01
  par value (1)
  2,052,006
  (4)
  $
  0.65
  (3)
  $
  1,333,804
  $
  169
  Common stock, $0.01
  par value (1)
  2,795,468
  (5)
  $
  0.88
  (6)
  $
  2,460,012
  $
  312
  Total
  $
  586
  (1)
  Each share includes one right to purchase shares of ATG's series A
  junior participating preferred stock pursuant to the terms of ATG's rights
  agreement dated September 26, 2001.
  (2)
  Represents shares issuable pursuant to stock options outstanding under
  the Primus 1999 Non-officer Stock Option Plan.
  (3)
  Calculated pursuant to Rule 457(h)(1) under the Securities Act of 1933
  based on the weighted average exercise price per share of the options
  outstanding under each of the stock option plans.
  (4)
  Represents shares issuable pursuant to stock options outstanding under
  the Primus 1999 Stock Incentive Compensation Plan.
  (5)
  Represents shares of common stock issuable upon exercise of the maximum
  number of stock options available for grant pursuant to the terms of the
  Primus 1999 Stock Incentive Compensation Plan.
  (6)
  Calculated pursuant to Rules 457(c) and (h)(1) under the Securities Act
  of 1933 based on the average of the high and low sale prices of the common
  stock as reported on the Nasdaq National Market on October 27, 2004.
  TABLE OF CONTENTS
  PART II
  Item 3. Incorporation of Documents by Reference
  Item 4. Description of Securities
  Item 5. Interests of Named Experts and Counsel
  Item 6. Indemnification of Directors and Officers
  Item 7. Exemption from Registration Claimed
  Item 8. Exhibits
  Item 9. Undertakings
  SIGNATURES
  EXHIBIT INDEX
  Ex-5.1 Legal Opinion of Foley Hoag LLP
  Ex-23.1 Consent of Ernst & Young LLP
  Ex-23.2 Notice Re: Consent of Arthur Andersen LLP
  Table of Contents
  PART II
  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  Item 3. Incorporation of Documents by Reference.
  The following documents, which we filed with the Securities and Exchange
  Commission, are incorporated by reference in this registration statement:
  (a) our annual report on Form 10-K for the year ended December 31, 2003,
  as amended by amendment no. 1 on Form 10-K/ A;
  (b) our quarterly report on Form 10-Q for the quarter ended March 31,
  2004;
  (c) our quarterly report on Form 10-Q for the quarter ended June 30, 2004;
  (d) our current report on Form 8-K filed on August 11, 2004;
  (e) our current report on Form 8-K filed on August 18, 2004;
  (f) our current report on Form 8-K filed on September 28, 2004;
  (g) our current reports on Form 8-K filed on October 12, 2004;
  (h) our current reports on Form 8-K filed on October 28, 2004;
  (i) our current reports on Form 8-K filed on November 1, 2004; and
  (j) the description of our common stock and related preferred stock
  purchase rights contained in our registration statement on Form 8-A filed with
  the SEC on July 12, 1999, together with amendments and reports filed for the
  purpose of updating that description, including the Form 8-A/A filed with the
  SEC on October 2, 2001.
  In addition, all documents subsequently filed by us pursuant to Sections
  13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended,
  prior to the filing of a post-effective amendment which indicates that all
  securities offered have been sold or which deregisters all securities then
  remaining unsold, are deemed to be incorporated by reference into, and to be a
  part of, this registration statement.
  Table of Contents
  Item 4. Description of Securities.
  Not Applicable.
  Item 5. Interests of Named Experts and Counsel.
  The validity of the securities we are registering is being passed upon by
  Foley Hoag LLP, Boston, Massachusetts.
  Item 6. Indemnification of Directors and Officers.
  Section 102 of the Delaware General Corporation Law allows a corporation
  to eliminate the personal liability of directors of a corporation to the
  corporation or its stockholders for monetary damages for a breach of fiduciary
  duty as a director, except where the director breached his duty of loyalty,
  failed to act in good faith, engaged in intentional misconduct or knowingly
  violated a law, authorized the payment of a dividend or approved a stock
  repurchase in violation of Delaware corporate law or obtained an improper
  personal benefit. The registrant has included such a provision in its charter.
  Section 145 of the Delaware General Corporation Law provides that a
  corporation has the power to indemnify a director, officer, employee or agent
  of the corporation and certain other persons serving at the request of the
  corporation in related capacities against amounts paid and expenses incurred in
  connection with an action or proceeding to which such person is or is
  threatened to be made a party by reason of such position, if such person shall
  have acted in good faith and in a manner he or she reasonably believed to be in
  or not opposed to the best interests of the corporation, and, in any criminal
  proceeding, if such person had no reasonable cause to believe his or her
  conduct was unlawful; provided that, in the case of actions brought by or in
  the right of the corporation, no indemnification shall be made with respect to
  any matter as to which such person shall have been adjudged to be liable to the
  corporation unless and only to the extent that the adjudicating court
  determines that such indemnification is proper under the circumstances.
  Article Eighth of the registrant's charter provides that no director of
  the registrant shall be personally liable for any monetary damages for any
  breach of fiduciary duty as a director, except to the extent that the Delaware
  General Corporation Law prohibits the elimination or limitation of liability of
  directors for breach of fiduciary duty.
  Article Ninth of the registrant's charter provides that a director or
  officer of the registrant:
  (a) shall be indemnified by the registrant against all expenses (including
  attorneys' fees), judgments, fines and amounts paid in settlement incurred in
  connection with any litigation or other legal proceeding (other than an action
  by or in the right of the registrant) brought against such person by virtue of
  his or her position as a director or officer of the registrant if such person
  acted in good faith and in a manner he or she reasonably believed to be in, or
  not opposed to, the
  Table of Contents
  best interests of the registrant, and, with respect to any criminal action
  or proceeding, had no reasonable cause to believe his or her conduct was
  unlawful and
  (b) shall be indemnified by the registrant against all expenses (including
  attorneys' fees) and amounts paid in settlement incurred in connection with any
  action by or in the right of the registrant brought against such person by
  virtue of his or her position as a director or officer of the registrant if
  such person acted in good faith and in a manner he or she reasonably believed
  to be in, or not opposed to, the best interests of the registrant, except that
  no indemnification shall be made with respect to any matter as to which such
  person shall have been adjudged to be liable to the registrant, unless a court
  determines that, despite such adjudication but in view of all of the
  circumstances, he or she is entitled to indemnification of such expenses.
  Notwithstanding the foregoing, to the extent that a director or officer
  has been successful, on the merits or otherwise, including the dismissal of an
  action without prejudice, such person is required to be indemnified by the
  registrant against all expenses (including attorneys' fees) incurred in
  connection therewith. Expenses shall be advanced to a director or officer at
  his or her request, provided that such person undertakes to repay the amount
  advanced if it is ultimately determined that he or she is not entitled to
  indemnification for such expenses.
  Indemnification is required to be made unless the registrant determines
  that the applicable standard of conduct required for indemnification has not
  been met. In the event of a determination by the registrant that the director
  or officer did not meet the applicable standard of conduct required for
  indemnification, or if the registrant fails to make an indemnification payment
  within 60 days after such payment is claimed by such person, such person is
  permitted to petition the court to make an independent determination as to
  whether such person is entitled to indemnification. As a condition precedent to
  the right of indemnification, the director or officer must give the registrant
  notice of the action for which indemnity is sought and the registrant has the
  right to participate in such action or assume the defense thereof.
  Article Ninth of the registrant's charter further provides that the
  indemnification provided therein is not exclusive, and provides that in the
  event that the Delaware General Corporation Law is amended to expand the
  indemnification permitted to directors or officers the registrant must
  indemnify those persons to the fullest extent permitted by such law as so
  amended.
  The indemnification provisions contained in our charter and by-laws are
  not exclusive of any other rights to which a person may be entitled by law,
  agreement, vote of stockholders or disinterested directors, or otherwise. In
  addition, we maintain insurance on behalf of our directors and officers
  insuring them against liabilities asserted against them in their capacities as
  directors or officers or arising out of such statuses.
  Item 7. Exemption from Registration Claimed.
  Not Applicable.
  Table of Contents
  Item 8. Exhibits.
  The following exhibits are included as part of this registration
  statement.
  Incorporated by reference
  Filed with this
  Exhibit Number
  Description
  Form S-8
  Form
  Filing date with SEC
  Exhibit number
  4.1
  Amended and Restated Certificate
  of Incorporation of Art
  Technology Group, Inc.
  S-8
  June 12, 2003
  4.1
  4.2
  Amended and Restated By-Laws of
  Art Technology Group, Inc.
  S-3
  July 6, 2001
  4.2
  4.3
  Specimen common stock certificate
  S-1/A
  July 13, 1999
  4
  4.4
  Rights Agreement dated September
  26, 2001 between Art Technology
  Group, Inc. and EquiServe Trust
  Company, N.A., as rights agent
  8-K
  October 2, 2001
  4.1
  5.1
  Legal opinion of Foley Hoag LLP
  X
  23.1
  Consent of Ernst & Young LLP
  X
  23.2
  Notice Regarding Consent of
  Arthur Andersen LLP
  X
  23.3
  Consent of Foley Hoag LLP
  (contained in Exhibit 5.1)
  X
  24.1
  Power of Attorney (included on
  the signature page of this
  registration statement)
  X
  Item 9. Undertakings.
  (a) The undersigned registrant hereby undertakes:
  (1) To file, during any period in which offers or sales are being
  made, a post-effective amendment to this registration statement:
  (i) To include any prospectus required by Section 10(a)(3) of
  the Securities Act;
  (ii) To reflect in the prospectus any facts or events arising
  after the effective date of the registration statement (or the most
  recent post-effective amendment thereof) which, individually or in
  the aggregate, represent a fundamental change in the information
  set forth in the registration statement. Notwithstanding the
  foregoing, any increase or decrease in volume of securities offered
  (if the total dollar value of securities offered would not exceed
  that which was registered) and any deviation from the low or high
  end of the estimated maximum offering range may be reflected in the
  form of prospectus filed with the Commission pursuant to Rule
  424(b) if, in the aggregate, the changes in volume and price
  represent no more than a 20% change in the maximum aggregate
  offering price set forth in the "Calculation of Registration Fee"
  table in the effective registration statement; and
  Table of Contents
  (iii) To include any material information with respect to the
  plan of distribution not previously disclosed in the registration
  statement or any material change to such information in the
  registration statement;
  provided, however
  , that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply
  if the information required to be included in a post-effective amendment
  by those paragraphs is contained in periodic reports filed with or
  furnished to the Commission by the registrant pursuant to Section 13 or
  Section 15(d) of the Exchange Act that are incorporated by reference in
  this registration statement.
  (2) That, for the purpose of determining any liability under the
  Securities Act, each such post-effective amendment shall be deemed to be
  a new registration statement relating to the securities offered therein,
  and the offering of such securities at that time shall be deemed to be
  the initial
  bona fide
  offering thereof; and
  (3) To remove from registration by means of post-effective amendment
  any of the securities being registered which remain unsold at the
  termination of the offering.
  (b) The undersigned registrant hereby undertakes that, for purposes of
  determining any liability under the Securities Act of 1933, each filing of the
  registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
  Exchange Act that is incorporated by reference in the registration statement
  shall be deemed to be a new registration statement relating to the securities
  offered therein, and the offering of such securities at the time shall be
  deemed to be the initial
  bona fide
  offering thereof.
  (c) Insofar as indemnification for liabilities arising under the
  Securities Act may be permitted to directors, officers and controlling persons
  of the registrant pursuant to the foregoing provisions, or otherwise, the
  registrant has been advised that in the opinion of the Securities and Exchange
  Commission such indemnification is against public policy as expressed in the
  Act and is, therefore, unenforceable. In the event that a claim for
  indemnification against such liabilities (other than the payment by the
  registrant of expenses incurred or paid by a director, officer or controlling
  person of the registrant in the successful defense of any action, suit or
  proceeding) is asserted by such director, officer or controlling person in
  connection with the securities being registered, the registrant will, unless in
  the opinion of its counsel the matter has been settled by controlling
  precedent, submit to a court of appropriate jurisdiction the question whether
  such indemnification by it is against public policy as expressed in the Act and
  will be governed by the final adjudication of such issue.
  Table of Contents
  SIGNATURES
  Pursuant to the requirements of the Securities Act of 1933, the registrant
  certifies that it has reasonable grounds to believe that it meets all of the
  requirements for filing on Form S-8 and has duly caused this registration
  statement to be signed on its behalf by the undersigned, thereunto duly
  authorized, in the City of Cambridge, Commonwealth of Massachusetts, on this
  2nd day of November, 2004.
  Art Technology Group, Inc.
  By:
  /s/ Robert D. Burke
  Robert D. Burke
  President and Chief Executive Officer
  POWER OF ATTORNEY
  KNOW ALL BY THESE PRESENTS that each individual whose signature appears
  below hereby constitutes and appoints Robert D. Burke and Edward Terino, and
  each of them, his or her true and lawful attorneys-in-fact and agents with full
  power of substitution, for him or her and in his or her name, place and stead,
  in any and all capacities, to sign any and all amendments (including
  post-effective amendments) to this registration statement, and to file the
  same, with all exhibits thereto, and all documents in connection therewith,
  with the Securities and Exchange Commission, granting unto said
  attorneys-in-fact and agents, and each of them, full power and authority to do
  and perform each and every act and thing which they, or any of them, may deem
  necessary or advisable to be done in connection with this registration
  statement, as fully to all intents and purposes as he or she might or could do
  in person, hereby ratifying and confirming all that said attorneys-in-fact and
  agents or any of them, or any substitute or substitutes for him or her, or any
  or all of them, may lawfully do or cause to be done by virtue hereof.
  Pursuant to the requirements of the Securities Act, this registration
  statement has been signed by the following persons in the indicated capacities
  as of November 2, 2004.
  Signature
  Title
  /s/ Robert D. Burke
  Robert D. Burke
  President, Chief Executive Officer and Director
  (Principal Executive Officer)
  /s/ Edward Terino
  Edward Terino
  Senior Vice President, Chief Financial Officer
  (Principal Financial and Accounting Officer)
  /s/ Paul G. Shorthose
  Paul G. Shorthose
  Chairman of the Board
  Table of Contents
  Signature
  Title
  /s/ David B. Elsbree
  David B. Elsbree
  Director
  /s/ John R. Held
  John R. Held
  Director
  /s/ Ilene H. Lang
  Ilene H. Lang
  Director
  /s/ Mary Makela
  Mary Makela
  Director
  /s/ Phyllis S. Swersky
  Phyllis S. Swersky
  Director
  Michael A. Brochu
  Director
  Daniel C. Regis
  Director
  Table of Contents
  EXHIBIT INDEX
  Incorporated by reference
  Filed with this
  Exhibit Number
  Description
  Form S-8
  Form
  Filing date with SEC
  Exhibit number
  4.1
  Amended and Restated Certificate
  of Incorporation of Art
  Technology Group, Inc.
  S-8
  June 12, 2003
  4.1
  4.2
  Amended and Restated By-Laws of
  Art Technology Group, Inc.
  S-3
  July 6, 2001
  4.2
  4.3
  Specimen common stock certificate
  S-1/A
  July 13, 1999
  4
  4.4
  Rights Agreement dated September
  26, 2001 between Art Technology
  Group, Inc. and EquiServe Trust
  Company, N.A., as rights agent
  8-K
  October 2, 2001
  4.1
  5.1
  Legal opinion of Foley Hoag LLP
  X
  23.1
  Consent of Ernst & Young LLP
  X
  23.2
  Notice Regarding Consent of
  Arthur Andersen LLP
  X
  23.3
  Consent of Foley Hoag LLP (contained in Exhibit 5.1)
  X
  24.1
  Power of Attorney (included on
  the signature page of this
  registration statement)
  X