I think this has been reported previously. I think shortly after the Novell deal came out Red Hat said they had talked to Microsoft but rejected the offer due to the patent provisions.
http://www.eweek.com/article2/0,1895,2059675,00.asp
"Mark Webbink, Red Hat's deputy general counsel, has all but ruled out any similar agreement with Microsoft, telling eWEEK that "we do not believe there is a need, or basis, for the type of relationship defined in the Microsoft-Novell announcement."
However, Red Hat "has and will continue to work with Microsoft on true interoperability and open standards in the way we did in advising them in the development of their Open Specification Promise," he said. "
November 15, 2006
I know that's not exactly the same thing, but reading between the lines, coupled with something else I remember reading something on the RH site, too, but can't find at the moment, seemed to indicate the parties had talked but that was it.
Update: Here we go. This was one of the articles I remember reading before:
http://www.informationweek.com/showArti ... =194400885
"Thursday, Microsoft's Ballmer said that the Redmond, Wash. developer was ready to cut a deal with Red Hat similar to the one it struck with Linux seller Novell last week. "We are willing to do the same deal with Red Hat Linux and other Linux distributors," Ballmer was quoted by the Seattle Post-Intelligencer during a Q&A at an SQL database conference.
...
Friday, Red Hat brushed off Ballmer."
Nov 17, 2006