DevOnLinux

As said here by Jeremy Allison, creator of SAMBA, also the mandrill of Devonlinux say no to Mono.

Software patents problem.

But the problem is that Mono is dangerous for Free Software. The heart of the matter is, as usual, software patents. Microsoft have patents on the technology inside .NET, and since the Tom Tom lawsuit, Microsoft have shown they are not averse to attacking Free Software using patent infringement claims.

Novell agreement with microsoft.

Miguel’s employer, Novell, has a patent agreement with Microsoft that exempts Mono users from Microsoft patent aggression, so long as you get Mono from Novell. Miguel takes pains to point this out. This is not a level playing field, or software freedom for all. This is a preferred supplier trying to pretend there is no problem. Sure there isn’t a problem, for them.

And all others?

It is vitally important to the continued success of the community development model that one part of the community does not enter into an agreement which gives some people patent protection while leaving other people out in the cold. That is why I was so opposed to the patent agreements recently entered into by Novell, Xandros and other companies.

This one is reported by Andrew Tridgell, negotiator with Microsoft for Samba.

Update 26-12-2009
Other valid reasons to say no to mono, moonlight, microsoft and the traitor de icaza.

developer Tom “spot” Callaway, Engineering Manager and Red Hat legal expert at Fedora, made it clear that the Fedora project, sponsored largely by Red Hat, will continue to leave the software out. One of the reasons was that the new promise does not protect Linux distributors any more than the old one did.