Xinuos loses appeal in long-running Linux and Unix legal battle

A decades-long legal battle over Unix code ownership and its relationship to Linux has reached a critical turning point. The U.S. Second Circuit Court of Appeals has dismissed an appeal by Xinuos against IBM and Red Hat, upholding a previous ruling from the U.S. District Court for the Southern District of New York.

The dispute traces back to 1998 and Project Monterey, a collaboration involving IBM, Santa Cruz Operation, Intel, and Sequent aimed at creating a Unix system for various processor architectures. As Linux gained dominance, IBM shifted its focus toward the Linux ecosystem, leading to allegations that proprietary Unix code from the Monterey project was improperly integrated into Linux.

Xinuos, which acquired the Unix intellectual property and related business from SCO in 2011, argued that IBM violated licensing agreements. However, the court determined that Xinuos's claims were barred by the statute of limitations and noted that while the company framed the case as a licensing dispute, the core issue remained code ownership. Although Xinuos intends to seek an en banc rehearing, legal experts suggest the probability of success is extremely low.