SCO has terminated IBM’s Dynix licence. Dynix was a product developed by Sequent, which was acquired by IBM in 1999. Technology developed by Sequent for its Unix OS (Dynix) called Numa was subsequently rolled into Linux. According to this article at Vnunet.com, it looks like a lot of this goes back to SCO’s bitterness about project Monterrey, a joint venture between SCO, Intel, and IBM. IBM withdrew from the project, which was SCO’s last chance at the big time.