ATG and AMS Launch Online Tax Application for Commonwealth of Virginia On ATG Dynamo; Based on Successful Small Business Application, iFile for Individuals Launched.

Business/Technology Editors

CAMBRIDGE, Mass.--(BUSINESS WIRE)--April 24, 2001

ATG (Art Technology Group, Inc. Nasdaq: ARTG) today announced the successful launch of the Commonwealth of Virginia's iFile application on the ATG Dynamo(R) e-Business Platform. An innovative online tax application developed by AMS for Virginia's Department of Taxation, iFile (http://www.tax.state.va.us/ifile) allows individuals and businesses the ability to file their taxes online. Launched as a VA TAX Online initiative, the iFile application is an example of how the government can use the Web to deliver fast, convenient services to citizens and taxpayers. Based on its successful small business application launched in March of 2000, the Commonwealth of Virginia brought its individual tax filing services online in 20 weeks, offering greater convenience to taxpayers in time for the 2000-2001 tax season.

"The iFile application was the Department's first attempt at delivering comprehensive and interactive customer services over the Internet and it is truly groundbreaking in a number of ways," said Danny M. Payne, Tax Commissioner. "We understood early on that we needed to be as flexible as possible, and develop an application that could be expanded to other tax types and across traditional government boundaries. ATG Dynamo gave us that flexibility, and is continuing to serve us well as we expand the functionality of the iFile application."

The VA Tax Online group's goal for iFile was to make the tax-filing process quick and simple for its customers, the taxpayers. Using ATG Dynamo, AMS created a site that offers businesses 24-hour access to file and pay their taxes, review their account history, and receive immediate confirmation of filed returns. These features all contribute to a faster tax filing process with fewer filing errors for taxpayers.

"When looking to create iFile, we knew we wanted to work with companies that understood our technology needs and our business objectives," said Farley Beaton, Business Project Manager, Partnership Project, Virginia Department of Taxation. "AMS's solid experience with government implementations combined with the technology strength of ATG Dynamo gave us just what we were looking for to complete iFile. With ATG Dynamo, we have a solid foundation for extending the online services we offer our constituents."

"ATG's entry to the government sector gives our customers access to a proven platform and personalization and commerce applications to help improve service while reducing the cost of these services to taxpayers," said John Radtke, AMS Project Manager. "Working with ATG Dynamo, we were able to implement the iFile application in only 20 weeks, bringing dramatic benefits to the citizens of Virginia."

"We expect the Internet to become a primary channel for government interactions in the near future," said Ian Reid, vice president marketing for ATG. "The Commonwealth of Virginia is using this powerful vehicle to improve the level of service it offers to taxpayers through added convenience, a faster process and less red tape. The iFile project will be a model for states as they move to the Web."

About AMS

American Management Systems (AMS) is an international business and information technology consulting firm with 2000 revenues of $1.28 billion. Founded in 1970, AMS leverages deep industry expertise to manage complex IT, eBusiness and systems integration projects for clients including 43 state governments, most federal agencies and hundreds of companies in the FORTUNE 500(TM). AMS is headquartered in Fairfax, Virginia, and has approximately 8,750 employees in 51 offices worldwide. Forbes magazine ranked AMS among "America's 400 best big companies," and Fortune magazine placed AMS 44th on its list of the "100 Best Companies to Work for in America" in 2000. AMS is traded in the NASDAQ under the symbol AMSY and can be found on the web at www.ams.com.

About ATG

ATG is a leading provider of customer management and e-commerce products and services. ATG offers an integrated suite of Java(TM) application server-based products and services, as well as related application development, integration and support services. The ATG Dynamo(R) e-Business Platform enables Global 2000 enterprises, as well as new businesses using the Internet as their primary business channel, to understand, manage and build their online customer relationships and to more effectively market, sell and support their products and services over the Internet.

With its network of more than 250 partners, ATG has delivered e-business solutions to over 670 companies worldwide including 3M, Aetna Services, Inc., American Airlines, Blockbuster, BMG Direct, eChips, Eastman Kodak, HSBC, Herman Miller, J. Crew and Sun Microsystems. The company is headquartered in Cambridge, Massachusetts with additional locations throughout North America, Europe, Asia and Australia. www.atg.com.

Dynamo, ATG and Art Technology Group are registered trademarks of Art Technology Group, Inc. All other product names, service marks, and trademarks mentioned herein are trademarks of their respective owners.

This press release contains forward-looking statements for purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995. These statements involve known and unknown risks and uncertainties that may cause ATG's actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by such forward-looking statements. Important risk factors affecting ATG's business generally may be found in ATG's periodic reports and registration statements filed with the Securities and Exchange Commission. Risk factors related to the subject matter of this press release include the possibility that the ATG software will not be able to handle the volume of the site; that the site will be unsuccessful or will not substantially enhance the user's Internet experience; and the risks and costs of intellectual property litigation. ATG undertakes no obligation to update any of the forward-looking statements after the date of this press release.