This is a step-by-step guide for building a GTK+ application on Win32 using Minimalist GNU for Windows (MinGW). I will do that by example, namely DFCGen (GTK+).

1. Download MinGW from http://www.mingw.org and install it on your Win32 operating system (i installed MinGW 20110802, using the associated installer mingw-get-inst-20110802.exe).¹⁾
2. Download an all-in-one GTK+ bundle from http://www.gtk.org/download/win32.php and extract the archive directly into the MinGW installation directory. Note: Be careful when overwriting files. I had some problems with intl/gettext, because MinGW installed libintl v1.2, but GTK wants to overwrite this with v1.1.
3. Start the MinGW shell (MSYS) and enter gtk-demo to verify your installation.
4. Download additional tarball source packages (at this example GSL from http://www.gnu.org/software/gsl) and extract it into a directory anywhere.
5. In MSYS shell change to that directory and do a package build:²⁾

   ./configure --prefix=/mingw; make; make install

6. Extract the tarball distribution package, in this example dfcgen-gtk-0.4.tar.gz to a directory, which is reachable by the MSYS shell.
7. In MSYS shell change to that directory and build the package (but do NOT a make install):

   ./configure; make

8. Now some handy work comes into play:
   • First create a new directory for gathering all Win32 installation files.
   • Copy the generated executable dfcgen-gtk.exe into this directory and change to it.
   • Copy the following directories from MinGW into this “gathering” pool:
     • /mingw/etc → ./etc
     • /mingw/lib/gtk-2.0 → ./lib/gtk-2.0
   • Create a sub-directory share and copy the following directories from dfcgen-gtk-0.4 in:³⁾
     • data/filters → share/filters
     • data/pixmaps → share/pixmaps
     • data/templates → share/templates
   • Start dfcgen-gtk.exe from a DOS shell or from the file manager. This will produce an error, stating that a DLL is missing. Typically this is a DLL from the GTK+ package, which can be found anywhere under /mingw (probably in /mingw/bin). Copy the DLL also into the directory where dfcgen-gtk.exe now resides.
   • Start dfcgen-gtk.exe again and repeat the procedure (until no error).
   • If you want another language than English (internationalization, i18n, locale, intl/gettext) copy also the following directories:
     • from the MinGW installation: /mingw/share/locale/de/LC_MESSAGES → ./share/locale/de/LC_MESSAGES
     • from the dfcgen-gtk build directory: po/de.gmo → ./share/locale/de/LC_MESSAGES/dfcgen-gtk.mo (file renamed).
9. Copy the “gathering” directory to your final Win32 installation directory, e.g. C:\programs\dfcgen-gtk. You can start dfcgen-gtk.exe directly from this location (or create a shortcut on your desktop).