Is it possible to redistibute a .net app compiled with vs to linux without
recompiling with say mon compiler?

And what if I import functions from external non-.net dlls like

[dllimport("fmod.dll")]
public static extern fmod_playsound(string file, int flags);

the library fmod itself is platform independent but there are certainly
different versions of the library for each plaform having different file
name and different internal image format, so how can such an issue be
solved?

Is it possible to call methods from an external dll without using the
dllimport attribute, something like GetProcAddress in the old days?