Have you looked at Mono? www.go-mono.com It's a dotNET C# compiler with
linux, Windows and OSX engines. It will require that the mono runtimes
are installed on the target machines, but that's not much different than
the NET requirements. If you're used to developing in windows, there's
sharpdevelop www.icsharpcode.net/OpenSource/SD/
Check it out, it might just be what you need.