In theory perl is a PVM. However in reality I found Perl often less compatible then claimed on various forums and places.

Compatible with what?

A multitude depends on an specific underlying function call or program, often only found in the Linux world. The use of a XS interface, often present in the modules without any mention in the documentation, can really break portability.

What does Perl having a VM have to do with portability, especially those of native libraries? That's the point, not a question. The OP is conflating two topics.