Mono is a bad idea even without patents. If you want a restrictive statically-typed bytecoded language from a corporation that’s a sworn enemy of Free Software, at least Oracle’s Java is under the GPL.
The FSF explain why even Microsoft’s latest charm offensive doesn’t make Mono any less dangerous –
And Microsoft have kindly provided a timely reminder –
Splitting Mono into two projects won’t help. Microsoft’s community promise (sic) covers only perfect implementations of current specifications of the core of what Mono implements. Implement that incorrectly, or implement anything else correctly, and you’re not covered. Splitting Mono just creates two patent threats rather than one. Don’t use Mono.