The Cygwin distribution contains thousands of packages from the Open Source world including most GNU tools, many BSD tools, an X server and a full set of X applications.If you're a developer you will find tools, headers and libraries allowing to write Windows console or GUI applications that make use of significant parts of the POSIX API.
The packages in the Net release are maintained by a large group of people; a complete list can be found here.
Please note that all of us working on Cygwin try to be as responsive as possible and deal with patches and questions as we get them, but realistically we don't have time to answer all of the email that is sent to the main mailing list. You can pick and choose the packages you wish to install, and update them individually.
He's the guy behind the current build and packaging system and maintains by far the most packages in the Cygwin distribution.
Jon Turney is developer and maintainer of the Cygwin X server and a couple of related packages.
If you are deploying to multiple systems, the best way is to run through a full installation once, saving the entire downloaded package tree.