See https://ci.appveyor.com/project/chcg/notepad-plus-plus/builds/28639632 for a testbuild with cmake. The mingw variant needs the changes from #4145 to complete successfully.

@chcg Since vcproj files and makefile are maintained now, what's the point of CMakeList.txt ?

By usage of cmake you could created make files for a lot of more build systems than just current MS vsproject or mingw make. You could generate vsproj files for different VS versions, jom, nmake, make, ninja, etc, see https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html.

Additionally it would be possible to add a packaging step via the cmake part cpack (https://cmake.org/cmake/help/latest/manual/cpack-generators.7.html#manual:cpack-generators(7))

But in the end that all just makes sense if it is maintained at least a little bit.