Also not clear is Microsoft's interest in these patents. In 2004, Novell hit Microsoft with an antitrust lawsuit, Microsoft tried to squelch competition in the office-productivity-applications market during the time that Novell owned WordPerfect, which is now owned by Corel.

The patents that would be acquired by CPTN in Attachmate's purchase of Novell probably wouldn't have that much bearing on the antitrust case, though, noted Charles King, Pund-IT's president and principal analyst of the Pund-IT analysis firm.

Another possible area of interest for Microsoft would be the IP around Unix held by Novell. In March, the U.S. District Court for the District of Utah that Novell owned the copyrights around Unix, between SCO and Novell over ownership rights.

Microsoft has asserted in the past that it owns some of the intellectual property in the Linux kernel, an open-source version of the Unix kernel. In 2006, Novell with Microsoft in which Microsoft agreed not to assert patent rights for any technology it may posses that would be in Novell's SUSE Linux distribution.

The deal "was controversial in the open-source community because Microsoft was less than transparent about where the actual IP infringements were," King said. The two companies also agreed to develop technologies that would help Unix and Microsoft Windows computers interoperate more smoothly.