I would like to request incorporating the latest version of expat library into Geant4 sources. That one already includes way better CMake configuration than what is currently in Geant4. I'm playing with building Geant4 on MinGW, but current expat configuration is suboptimal and it would take quite a bit of work to adapt it for non-VC compilers. The latest version of expat compiled out of the box for me and it worked when I try to use GEANT4_USE_SYSTEM_EXPAT on windows (with some tweaking of existing CMake sources in Geant4). (The problem with MinGW and current CMake configuration for expat is that it completely ignores any features that might exist and the compilation breaks thinking that MEMMOVE is not available.) Thank you.