Avistar's New Video Integration With IBM Lotus Sametime 7.5 Showcased at IBM Lotus Technical Forum 2006; Avistar Delivers ''Face-to-Face'' Interactivity to IBM's Innovative Enterprise Collaboration Platform.

KARLSRUHE, Germany & REDWOOD SHORES, Calif. -- Avistar Communications Corp. (NASDAQ:AVSR), a desktop video platform provider, today announced an innovative convergence of collaboration technologies that brings the power of "face-to-face" video interactivity to the widely used IBM Lotus Sametime real-time collaboration platform. IBM and Avistar will demonstrate this presence-based integration with IBM Lotus(R) Sametime(R) 7.5 during "Future Insights -- The Road Just Ahead," the keynote presentation at the IBM Lotus Technical Forum 2006 from May 15-17 in Karlsruhe, Germany.

"The reality of converged instant messaging, voice and video isn't a matter of 'if,' but 'when,'" said Ken Bisconti, Vice President, Workplace, Portal and Collaboration Products, IBM. "Combining IBM's enterprise collaboration tools with Avistar's video capabilities will provide our customers with advanced multi-dimensional communications tools to help them become more productive in the work they do everyday."

Avistar has developed a plug-in that embeds its video collaboration solution into the user interface of Lotus Sametime 7.5, IBM's next-generation IM and web conferencing solution. This seamless integration will help businesses to accelerate effective employee communication and react quickly to market changes and opportunities by incorporating desktop visual communications and other collaboration tools into key business processes. Avistar's plug-in is built on the Eclipse open source framework -- the same platform on which Lotus Sametime 7.5 is built.

"Organizations are increasingly recognizing the benefits of providing employee access to a collaboration platform integrating video, instant messaging, web conferencing and other capabilities," said Gerry Kaufhold, a principal analyst with In-Stat. "These tools -- embedded within the Lotus Sametime 7.5 platform -- can help increase employee productivity and the quality of decision-making to create a significant competitive advantage."

Integrating Avistar's video operating system, AvistarVOS, with Lotus Sametime 7.5 will provide users with "click-to-call" capabilities, delivering instant two-way and multi-party video conferencing from a video presence-enabled "buddy list." Future phases of the integration are planned to video-enable the Lotus Sametime 7.5 Web conferencing application and add Avistar's full suite of features, including interactive broadcasting and video content recording and publishing.

Extending seamless desktop video capability to additional IBM software applications, Avistar also announced today the release of AvistarVOS v8.5.1. This latest version of Avistar's advanced video operating system is integrated with the IBM Workplace Managed Client 2.6.

With this newly released integration, Avistar is supporting contextual collaboration among users, enabling them to connect by video from within Workplace Managed Client applications such as calendaring, contacts, e-mail and documents. Colleagues can interact "face-to-face" in one-to-one or multi-party video calls, share live data and record content for later viewing or distribution using the web or e-mail. This integration has earned Avistar the Lotus Advisor Editors' Choice Award in both 2005 and 2006, as well as recognition as a finalist for the 2005 IBM Lotus Chief Technology Officer Award.

"Visual collaboration is a key component of effective communication and a requirement for developing innovative ideas that solve business challenges fast," said Gerald J. Burnett, Chairman and CEO of Avistar. "By video-enabling business interactions using IBM collaboration tools, organizations are able to incorporate visual communication into crucial business processes at the right time and in the right place -- at the desktop, where work gets done more quickly."

AvistarVOS v8.5.1 with Workplace Managed Client integration is available now. Avistar's integration with Lotus Sametime 7.5 will be released during the Fall of 2006. Existing Avistar customers can upgrade to AvistarVOS v8.5.1 at no charge as part of their maintenance agreement. For more information, visit www.avistar.com.

About Avistar Communications Corporation

Avistar Communications Corporation develops, markets, and supports a video collaboration platform for the enterprise, all powered by the AvistarVOS(TM) software. From the desktop, Avistar delivers business-quality video calling, recording, publishing to web and emails, video-on-demand, broadcast origination and distribution, and document sharing. Avistar video-enables business processes by integrating visual communications into the daily workflow and connecting communities of users within and across enterprises. Founded in 1993, Avistar is headquartered in Redwood Shores, California, with sales offices in New York and London. Avistar's technology is used in more than 35 countries.

Collaboration Properties, Inc. (CPI), a wholly owned subsidiary of Avistar, holds a current portfolio of 70 patents for inventions in the primary areas of video and network technology. CPI pursues patents for presence-based interactions, desktop video, recorded and live media at the desktop, multimedia documents, data sharing, and a rich-service network video architecture to support Avistar's product suite and customers. CPI offers licenses to its patent portfolio and Avistar's video-enabling technologies to companies in the video conferencing, rich-media services, public networking, and related industries.

Forward-Looking Statements

This press release contains forward-looking statements including statements regarding the performance, impact and benefits of Avistar's suite of video applications and the integration of such applications with IBM's products. In some cases, these forward-looking statements can be identified by words such as "expects," "expected to," "intends to," or "plans." Such statements are subject to risks and uncertainties that could cause actual results to differ materially, including such factors, among others, as technical difficulties, difficulties and delays in completion of the integration process, the development of competitive technology and solutions and delays in adoption or acceptance of video collaboration technology. We refer you to the documents that Avistar files from time to time with the Securities and Exchange Commission, in particular the section entitled "Risk Factors" in Avistar's annual report on Form 10-K and its quarterly reports on Forms 10-Q.

For more information, visit www.avistar.com.

Copyright (c) 2006 Avistar Communications Corporation. All rights reserved. Avistar, AvistarVOS, and the Avistar logo are trademarks or registered trademarks of Avistar Communications Corporation. IBM, Lotus, Workplace Managed Client and Sametime are trademarks of International Business Machines Corporations in the United States, other countries or both. Other company, product or service names may be trademarks or service marks of others.