Incredibly, an effort lead by Flávio Soibelmann Glock is working to actually implement Perl 6 in Perl 5. You can download v6-alpha now on CPAN to try it out. It's feature set has not caught up with pugs yet, but there is steady progress on it.

Perl 6 features are also coming to Perl 5 in other ways. As described below, a number of Perl 5 modules already implement some Perl 6 features, and some aspects of Perl 6 are being added to the official 5 releases, starting with Perl 5.10.

Perl 5 modules implementing Perl 6 features

• Perl 5.10 provides some Perl 6 features that you can selectively turn on. See the Official Perl 5 Wiki for more information.
• There are many modules that currently implement parts of Perl 6 in Perl 5. Go to CPAN and do a module search on perl6.
• (Note: (http://search.cpan.org/modlist/Perl6) is missing many entries. Use the search above for the time being.)
• Some of these are listed on the PerlNet Perl 6 page.