The MRI 1.9 on Windows series has well known performance regressions and has for some time. This project's goal is to find and fix the issues, and get the fixes committed back into mainstream MRI.
It's like watching your old reliable Honda develop transmission problems and struggle to get over 45 MPH. Rather than retiring it to the shredder, folks have pulled it into The Code Shop for repairs.
MRuby is currently built using revision controlled Makefiles. We think a more maintainable and flexible solution is to leverage an automated build system. As such, we are creating a CMake-based prototype for review and potential acceptance into the upstream codebase.