"In early 2003, Microsoft started paying SCO what eventually grew to $16.6 million for a Unix license, according to regulatory filings. Only longtime Unix fan Sun Microsystems previously paid close to that, with a $9.3 million license deal."

http://www.zdnet.com/article/fact-and-fiction-in-the-microso...

Microsoft statement: "Microsoft does have a deal with SCO that has been widely reported. We paid SCO for licensing rights to ensure IT interoperability for UNIX migration technology, currently in use in Microsoft Utilities for UNIX-based Applications."

http://blog.seattlepi.com/microsoft/2006/10/09/a-new-microso...

Microsoft SCO conspiracy theory quashed (again) http://www.theregister.co.uk/2006/10/11/sco_microsoft_black_...