Once viewed as the penultimate operating system, UNIX was created in the 1960's alongside the C programming language at AT&T. (Microsoft licensed the technology from AT&T in the 1980's for its Xenix OS, a UNIX version that ran on IBM and compatible PCs.) IN 1992, Novell bought UNIX, and then the company sold the technology to SCO in 1995. Because most major companies that develop UNIX products, such as Sun, license the technology from the owner of UNIX, the technology is still fairly lucrative. But UNIX has been running out of steam in recent years, due to the success of Microsoft Windows NT (and later versions) and a UNIX clone called Linux. Created as an open source project, Linux source code is available to anyone.
And that's the problem, SCO says, and the company believes Linux contains significant portions of patented UNIX source code. If that's true, any companies selling or creating Linux projects could be at legal risk; SCO recently threatened to revoke IBM's UNIX license as early as next month. Microsoft says its taking the high road and licensing the technology specifically so that it can improve interoperability between Windows and UNIX and, in the process, preserve SCO's intellectual property rights. SCO notes that Microsoft isn't the only major vendor to acquire a UNIX license in recent days, though the company isn't naming names yet.