There three perl FFI's.
There is the first and worst and most popular:
This works only on Win32, hence the name. But only with MSVC compilers. Cygwin not. Well, Calls do work, just Callbacks not.
This module I recently took over from John Tobey. Well, this has much more to offer, but is also a hack and failed to work for modern GCC versions.
This is the simpliest and easiest to use, has the most natural interface, but uses the actively maintained external ffcall library and therefore works out of the box on almost every platform.