How can it be compiled on Linux?
I don't know programming. But it looks the game don't need to be compiled, XML and lua define all rules running on springrts engine.
C# part is mainly server side and editing tools. And also the most popular SpringRTS lobby zero-k lobby, which was compatible with Mono but later dropped due to no Linux maintainers.
Let's watch http://pyweek.org
>How can it be compiled on Linux?
You don't need to build it because it's a Spring-Mod.