This. I maintain a project that has to build about 28,000 object files. It takes less than a minute on Linux. Even though our binaries run on Windows, we willfully choose not to support building them on Windows. I tell people, trust me, it'll compile so much faster if you just create a Linux VM on your Windows computer and then run make there. But they never believe me until they see it with their own eyes. vfork() is a thing. It also helps to not have to fsync() on close() due to shortcomings with win32.