It's written in .NET so if you wished, you'd have two options:
-"Remove" DX stuff //put it in compiler "ifs"// and force opengl, using mono, plus all that extra windows stuff -Rewrite most-likely-to-be-used features on another language with native libs.
Or a progressive port via the second option.
So, I'd do it, but I'm not good enough at coding for doing this.