I have successfully built Pound on cygwin but so far not a great 
deal of luck on Interix (Microsoft's Services for Unix). 

I can build on Interix with some tweaks:

./configure --with-ssl=<my ssl dir>

On Interix there isn't sys/poll.h only poll.h
I changed 
   #define HAVE_SYS_POLL 1
And changed the header to 
   #include <poll.h>

And also this:

   #define socklen_t int

However, the poll() doesn't seem to work.

Any help or guidance would be appreciated.

Thanks.

Chui