+11  Q: 

P/Invoke in Mono

What's the current status of Mono's Platform Invoke implementation on Linux? And on Solaris?

+11  A: 

Working, usable and stable. It's well tested since quite a lot of mono's own low-level functionality has to be marshaled through it to the underlying operating system.

There are some P/Invoke extensions when compared to Microsoft .Net implementation (after all they deal with a single OS family and three architectures at most). Most notable of those would be that library mappings transform the library name to OS-specific variants (e.g. mylib.dll searches for on Linux, mylib.dylib on OS X and so on) and take into account various other system specific conventions. There is also a DLLMap configuration extension which can be used if the default name translations are not enough. Usually it's convenient to have the same API of the binary lib exposed on different OSes, so that migrating between platforms only requires changes in the C code, not the .Net part.