IO Speedup, More Dramatic Still (Parrot VM)

Is parrot friendly about mixing and matching libraries? If there's a library available in perl, how hard is it to use those libraries from another language in the same process? If not parrot, are there are other VMs that are friendly like this?

The reason I ask is that the most important thing about a language platform seems to be available libraries. But I wonder whether that's necessarily language bound - shouldn't it be more a VM issue?