The C part of the compiler has always worked with Win32, but key parts (threads, TCP sockets, debugger) where missing in the PDEE. I have added them, so the HTTP server now works on Win32.
The Win32 kernel functions prototypes are in /pliant/language/os/win32.pli
There are still some missing functions (mainly in /pliant/admin/file.pli and /pliant/language/stream/native.pli files), but it should be no problem for testing Pliant and very easy to add the missing parts.