Use of cygwin on windows Platform

[MyBabyJoeJoe]

I am interested in looking at log4j as a logging mechanism for two
applications currently slated for rollout in the next two months.

My question is about the use of cygwin as a part of that process:
1. Is it used ONLY during deployment, or at runtime also?

2. Do I also need the gnucc compiler for creation?

As a non-Unix  developer and deployer, I am not conversant with all of the
Unix based utilities, and their use, and wonder why these added pieces are
part of an "All Java" solution...

I need to justify the installation of additional software, and provide
assurances to the auditors that this additional software is both necessary
and safe.