Press Release Source: Avistar Communications Corporation Fourteen of Microsoft Re-examination Challenges of Avistar's U.S. Patents Rejected by U.S. Patent Office Monday June 2, 7:00 am ET SAN MATEO, Calif., June 2 /PRNewswire-FirstCall/ -- Avistar Communications Corporation (Nasdaq: AVSR - News) has received notification from the U.S. Patent & Trademark Office (the "USPTO" or the "Patent Office") that as of the close-of-business on Friday, May 30, 14 of Microsoft Corporation's (Nasdaq: MSFT - News) requests for the Patent Office's re-examination of Avistar's 29 U.S. patents have been rejected. ADVERTISEMENT Avistar is represented by Paul Carmichael as its primary licensing advisor. Among many executive assignments, Paul has served as Apple Computer Inc.'s Associate General Counsel for Patent and Trademark and Acting General Counsel, and in prior work, as IBM's Senior Corporate Counsel for Intellectual Property Law during a thirty year career at IBM. "Data for the entire history of USPTO's re-examination activity indicate that only 8% of re-examination requests are rejected," stated Paul Carmichael. "While we believed that Microsoft's challenge to Avistar's entire U.S. patent portfolio was without merit, we also recognized that the statistics relating to us avoiding a wholesale re-examination were against us. We are delighted that the Patent Office's review has resulted in this extraordinary result which validates and strengthens many of Avistar's most important patents, We expect that the 9 patents that the USPTO has agreed to re-examine at this point also will be validated, and actually strengthened, through this process." As discussed in Avistar's February 25, 2008 press release announcing the re-examination requests filed by Microsoft, the challenged Avistar patents have an important early priority date (1993), have already been examined over a large body of prior art, and include patents that have successfully withstood two litigations. Based on the history of these patents and the USPTO's response this week, Avistar is confident it will overcome any of the remaining re-examination requests that may be granted. Avistar patents have industry wide applicability to audio, video and data unified collaboration products and services. Simon Moss, CEO of Avistar, stated "we are obviously pleased with the USPTO's notification that challenges to the core 14 of our U.S. patents have been rejected. We continue to remain focused on our business operations and have no further comment at this time with regards to our patent discussions." Forward Looking Statements Statements made in this news release that are not purely historical, including but not limited to statements regarding Avistar's ability to overcome the remaining re-examination requests, the applicability of Avistar's patents to Microsoft's present and future products, the impact and end result of the re-examination process on the patents that are re-examined by the USPTO, are forward-looking statements within the meaning of Section 21E of the Securities Exchange Act. Such statements are subject to risks and uncertainties that could cause actual results to differ materially, including such factors, among others, as uncertainty associated with the USPTO's review and determination process, the time and expense to Avistar of responding to the re-examination requests and defending its patent portfolio, difficulties associated with enforcing or licensing Avistar's patent portfolio during the review and possible re-examination process, and the risk that Avistar's existing and pending patents could be revoked by the USPTO. As a result of these and other factors, Avistar expects to experience significant fluctuations in its licensing activities and operating results, and there can be no assurance that Avistar's future results will meet expectations. These and other risk factors are discussed in Avistar's Annual Report on Form 10-K and Quarterly Reports on Form 10-Q filed with the Securities and Exchange Commission from time to time. Avistar disclaims any intent or obligation to update these forward-looking statements. About Avistar Communications Corporation Avistar creates technology that provides the missing critical element in unified communications: bringing people in organizations face-to-face, through enhanced communications, for true collaboration anytime, anyplace. Its latest product, Avistar C3, draws on over a decade of market experience to deliver a single-click desktop videoconferencing and collaboration experience that moves business communications into a new era. Available as a stand-alone solution, or integrated with existing unified communications software from other vendors, Avistar C3 users gain instant messaging-style ability to initiate video communications across and outside the enterprise. Patented bandwidth management enables thousands of users to access desktop videoconferencing, Voice over IP (VoIP) and streaming media, without requiring substantial new network investment or impairing network performance. Avistar's desktop videoconferencing and collaboration installations are among the world's largest, including more than 18,000 seats sold in more than 40 countries. Clients report as much as a 20 percent reduction in travel expense and carbon emissions, increases in productivity, and immeasurably improved relationship building within their organizations, as well as with suppliers and customers. Avistar holds a portfolio of 80 patents for inventions in video and network technology and licenses IP to videoconferencing, rich-media services, public networking and related industries. Current licensees include Sony Corporation, Sony Computer Entertainment Inc. (SCEI), Polycom, Inc., Tandberg ASA, Radvision Ltd. and Emblaze-VCON. For more information, visit www.avistar.com ------------------------------------... Source: Avistar Communications Corporation