Israeli software vendor Emblaze has accused Microsoft of infringing its media streaming technology patent, having already accused Apple of the same offence.
Emblaze told Reuters it has sent letters to both companies and offered them the option of licensing the technology. According to the Israeli firm, Microsoft's IIS Smooth Streaming (used in Silverlight software) and Apple's HTTP Live Streaming Application (used in iPhone, iPod Touch, iPad and OS X) infringe its US patent.
Microsoft reportedly has until 15 March to reply, but it is unclear whether there is a deadline for Apple.
"While we are happy to license our technology to third parties, we will vigorously defend our rights and our competitive position," Emblaze chairman Naftali Shani told Reuters.