gtkmm and Win32
One of the major advantages of gtkmm is that it is crossplatform. gtkmm programs written on other platforms such as GNU/Linux can generally be transferred to Windows (and vice versa) with few modifications to the source.
gtkmm currently works with the MinGW/GCC compiler with a compiler version that supports C++17, such as gcc 7 or 8. It also works with Microsoft Visual C++ 2017 15.7.x or later (including the freely available express/community editions) on the Windows platform. There is an installer available for gtkmm on Microsoft Windows, but as of this writing (October 2020) it has not been updated for a long time. Please be aware that although normally it is fine to mix builds done with Visual Studio 2017 and 2019, please do not do so when building gtkmm with its -mm dependencies.