This is the rather outdated list of implementations of Perl 6 as of 2011
Please find more up-to-date information on http://perl6.org/compilers/
Original List with updated notices
There is no official or reference Perl 6 implementation, as exists with Perl 5. Instead, there is a language specification that began with Apocalypses and evolved through Exegeses and Synopses. Recently, the test suite is what actually defines the language properly. The Synopses and test suite continuously evolve together. Even though only one compiler is currently actively being developed, Larry Wall has clarified that anything that passes the test suite is Perl 6. With the feedback gained from the implementations, the Synopses and the test suite that forms the language specification are evolving. This page is about the various partial implementations that exist, which can parse and execute Perl 6. Virtual machines and runloops are excluded because they do not deal with Perl 6 source code.
- Niecza used to be the fastest implementation by far. The development was lead by Stefan O'Rear. It is now very far from feature-parity with Rakudo, though.
- viv is a derivation of STD.pm for testing and bootstrapping purposes. A utility called "gimme5" creates viv by translating STD.pm into Perl 5. This is possible because Larry very carefully wrote STD.pm in a translatable subset of Perl 6.
- Elf is a compiler written in Perl 6 with Perl 5 and Lisp backends.
- vill connects STD.pm to the LLVM (Low Level Virtual Machine) compiler tools.
- Perlito, formerly known as MP6 (mini Perl 6), is a Perl 6 subset build by Flavio Glock for bootstrap purposes.
- v6 is a Perl 6 compiler for Perl 5.
Historical Implementations are definitely closed projects.