[Stasyan]

But Microsoft is not in charge of Mono, plus Microsoft is applying Community Promise to Mono (http://www.microsoft.com/interop/cp/default.mspx).

this is from QA section:

Q: Is this Community Promise legally binding on Microsoft and will it be available in the future to me and to others? A: Yes, the CP is legally binding upon Microsoft. The CP is a unilateral promise from Microsoft and in these circumstances unilateral promises may be enforced against the party making such a promise. Because the CP states that the promise is irrevocable, it may not be withdrawn by Microsoft. The CP is, and will be, available to everyone now and in the future for the specifications to which it applies. As stated in the CP, the only time Microsoft can withdraw its promise against a specific person or company for a specific Covered Specification is if that person or company brings (or voluntarily participates in) a patent infringement lawsuit against Microsoft regarding Microsoft’s implementation of the same Covered Specification. This type of “suspension” clause is common industry practice.

So it looks like that Mono is better off than JVM and Java