Parrot: Revision 5
Parrot is the VM (a software virtual machine CPU) that was originally designed for Perl 6, but which is also intended to be a generally dynamic-language-friendly platform for Python, Ruby, and many other languages. This will also allow such languages to more easily interoperate, and to share libraries (parroting CPAN, as it were).
Parrot is the VM (virtual machine) that the Rakudo (Perl 6) compiler is built on, just as Pugs (Perl 6) is built on Haskell (although Pugs can also emit code for Parrot).
Because Parrot's objectives extend well beyond the Perl community that gave rise to it, the Parrot Foundation was founded in fall, 2008. This simplifies some organization and funding issues for Perl Foundation folks, while likewise making life easier for Parrot Foundation folks. Here are the new homes for these Parrot-related pages:
Parrot exists because other VMs (like the JVM and CLR) did't (and mostly still don't) have strong (and efficient) support for 100% of the super-dynamic language features of Perl 6. And while support for these features has improved in the past few years, leading to projects like IronPython, these VMs are still primarily designed for (biased towards) static languages.
Parrot also incorporates a number of other important and noteworthy innovations (for example, it's a register-based virtual machine).