Xenix: Microsoft's forgotten Unix-based operating system

Long before Linus Torvalds wrote Linux, Microsoft was the king of Unix world. The company, somehow, developed Xenix, the most popular version of Unix of its time. However, IBM's decision to go ahead with MS-DOS in its PCs acted as a death blow to Xenix and Microsoft lost interest in the OS.The article's light on details and content, but I figured it'd be an interesting excuse to ask if any of you ever used Xenix in any serious fashion. So, did any of you?