Welcome to the Grokline Project: Grokline’s UNIX Ownership History Project
From the site:
This is an open, community-based, collaborative research project, a living history, designed to carefully trace the ownership history of UNIX and UNIX-like code with the goal of reducing, or eliminating, the amount of software subject to superficially plausible but ultimately invalid copyright, patent and trade secret claims against Linux or other free and open source software. If there is any code out there that represents a conceivable risk of that kind, we’d like to identify it and mitigate the litigation risk now. If there isn’t any valid claim that can be made, we’d like to be able to prove it.