I once heard of a guy managed to install original Microsoft .Net Framework on Linux and successfully run Mono-incompatible .Net applications using bleeding-edge MS C# features. Any idea how could he do it?
Wine has .NET 2.0 working and sort of has .NET 3.0 working, beyond that and you're out of luck. Even then I think they're probably spotty at best. The best support for .NET on Linux is Mono. Mono has pretty good support for much of the .NET Framework but your still out of luck for .NET 4. http://www.mono-project.com/Compatibility