These are either: (1) UNIX environments for Windows, or (2) IDEs. I haven't really done much more than find the links here. Except for Cygwin, I haven't really used any of these. I do have experience using Cygwin over the last 3 years. I plan to come back to this page and review each of the environments below after I finish the languages section.

For now, if you have any MS Windows from 98 up, I have to recommend Cygwin. Cygwin is an excellent Unix emulating environment that occupies a directory under the C: drive (the default, you could put it into D:). It doesn't alter the registry, you can easily add additional utilities to it as desired, and it supports the X Windowing system thru an implementation of X from X.org.