licensing issue

["jerry jose" <jerry4u4@gmail.com>]

respected,

i  would  like to  implement the services of Freeradius server for one
of our upcoming  projects(Voip based application).i  would like  some
information regarding :

1)i would like the server to  interact with one of our clients
programs and perform some some data retrieval tasks,ie the server
recieves a request and will  call an external program to perform the
remaining  tasks.i  would like to  know whether such an external
program would  come under GPLV2 or 3.The server  performs the
redirection the rest processing is performed by our application, the
result  will  be notified by the server to  the client.

2)can freeradius be used in windows (with cygwin)

awaiting  your reply.

regards