It's a good bet that there's never been anything like Parrot before.

I'd take that bet.

Back in the eighties I did a lot of work with Poplog, a programming environment that had Lisp, Prolog, ML, Pop-11 and a few other languages all compiling down to a single virtual machine, which was in turn incrementally compiled down to raw machine code. Ran on VMS and most Unix platforms.

The VM was stack based, rather than register based as Parrot is, but there certainly isn't anything new about a cross-platform VM that was built to be the target for many different languages.

Parrot's just following in the grand Perl tradition of stealing the best ideas and implementing them well :-)

(If anybody is interested Poplog is still around. It's open source, runs on VMS, Windows9X/NT and a variety of versions of the Unix operating system (including Linux, AIX, Ultrix, SunOS, HP-UX and Dynix), on a variety of processors including VAX, M680x0, SPARC, 80x86, and MIPS. See poplog.org for info.)