Quoting from the Stream Theory official announcement:
Streaming application technology provider Stream Theory today filed a lawsuit against Softricity, AppStream and Exent claiming the three companies are infringing on its U.S. patent number 6,453,334.
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Stream Theory stated the U.S. patent office issued the patent on September 17, 2002. The patent describes “Method and apparatus to allow remotely located computer programs and/or data to be accessed on a local computer in a secure, time-limited manner, with persistent caching.” The patent application was originally filed with the U.S. Patent Office on June 16, 1997, and is believed to be the earliest patent in the field of streaming software.
What is really interesting here is that the lawsuit has been filed after Microsoft disclosed Softricity acquisition intentions…