At NICE we make use of GTK+ on Windows, Linux and OSX on our product Desktop Cloud Visualization. Till now we managed to do everything with the released versions of GTK we were getting from gtk.org but we are in a point where we need the new features from GLib and there are no new versions for Windows. The point, we were checking all the possibilities out there, sbuild, hexchat’s, using fedora’s mingw binaries, using suse’s mingw binaries… Either they did not provide all the packages or they just provided the packages for win32 and not for win64 but we did not manage to have a bundle of the gtk’s libraries.
As you may know Tarnyko was the previous person in charge of making the GTK bundles, he did a really good job and he also provided a build system to setup the build system and build all the required libraries. The problem is that it was not setup in a git repository, it was providing all the tarballs and it was not easy to update them, since you would have to download the tarball, replace the old one and update the scripts to build it. What we did was to take this build system and improve it so things are a bit more automated, so at the end you just have to update the version number to get the new version of the library built, we’ve also set it up so it builds glib 2.40 and gtk2 2.24 and gtk3 3.12.
We have released this new build system under the GNOME repository: https://git.gnome.org/browse/gtk-builder-win
If you have any doubts, you want to contribute to it (please do it!) feel free to send us a mail, contact either me or pbor on the gtk+ channel of the IRC.