The FFI and FFI::Library modules implement a foreign function interface 
for Perl.  The foreign function interface allows Perl code to directly 
call C functions exported from shared libraries (DLLs on Windows, .so 
files on Unix). It also allows a Perl subroutine to be packaged as a 
function which can be passed to an external C routine ("callbacks").

There are two modules in the package:

    * FFI is a low-level interface, providing two functions, call() and
      callback(). The call() routine expects to be passed a "raw" function
      address, but the module provides no way of creating such an address.
      That is left to other modules.
    * FFI::Library encapsulates the concept of a shared library. It offers
      functions to load a library (and to automatically unload it when it is
      no longer required), and to extract functions from the library, in a
      form suitable for calling from Perl.

See the file INSTALL for installation details.
