Updates to this story
Israeli firm Emblaze has told Microsoft that its IIS Smooth Streaming system infringes its US patent for media streaming technology.
It has invited Microsoft to license the patent and has asked Redmond for an answer by the 15 of March this year.
And Emblaze hasn't stopped with Apple. It's just sent out a notice to Apple and claims the same patent is infringed by Apple's HTTP Live Streaming Application used in the iPhone, the iPod Touch and the iPad. And in the Mac OS X operating system.
Emblaze has also invited Apple to license its technology.
It s own Live Streaming technology will be used in a mobile device called First Else, produced by one of its subsidiaries.
In a prepared statement, Naftali Shani, Chairman of Emblaze, said: "Emblaze has made substantial investment into research and development to build a rich portfolio of intellectual property over many years. While we are happy to license our technology to third parties, we will vigorously defend our rights and our competitive position".