I've been working very slowly on getting sb-bsd-sockets working on the sbcl/win32 port. It actually isn't too bad. The biggest hurdle is my own lack of understanding with how sb-alien works. sb-alien is the foreign function interface for sbcl that allows talking with external C libraries. In this case, I am making calls to ws2_32.dll - the winsock2 implementation on Windows XP and the like. I've been slowly building up the definitions for the alien interface for all of the underlying functions like socket, bind, accept, recv and the like. I was able to send my first message from an OS X box to the win32 sbcl instance last night. To give you an idea how rough it is right now, I was looking at what I received one character at a time with (deref (deref buf 0) 0).