The real problem isn't that MRI gobbles up memory when loading libraries, but that it is constitutionally incapable of sharing that memory between processes. I

The real problem isn't that MRI gobbles up memory when loading libraries, but that it is constitutionally incapable of sharing that memory between processes. If it didn't have such a ridiculous mark-and-sweep GC that insists on periodically writing to every damn page, libraries loaded before calling fork() would be optimally shared by the descendants.