And as others have mentioned upthread, Mosix was an extension to Linux that also implemented fork() in such a way that the child could be local or remote with file handles retained across the cluster. We had a Linux lan party when I was in college and managed to scrape together a Mosix cluster across a bunch of machines.
No. VM migration moves entire virtual computers. Forking makes a copy of a process with the current state; this moves that single duplicated process to a different machine.
