MinGW

MinGW is a distribution of the well-known GCC compilers, intended to be used by Microsoft Windows users (since GCC is primarily used on Unix/Linux platforms).
MinGW structure and installation/update is somewhat similar to Cygwin structure and installation: you can choose from several components to download, and download them for installing, or just download them to be used as shared libraries.

The executable file acts as an updater tool, or an add/remove components wizard. A base installation performs about 15 MB of downloads, so if you have a standard ADSL connection you will not have to wait long.

Once you get your MinGW distribution up and running, you can use it from the command line to access the executables directly and compile your source code, or to point your favorite IDE to the compiler executable, leveraging developer's productivity.

MinGW needs some training and practice to take full advantage of it. As a small set of command-line binaries, it may not be suitable for beginners.