I've always kept half an eye on the progress of the long, long, LONG awaited Perl 6, and more specifically on its cross-platform, dynamically typed VM at its base, Parrot.
One of the more exciting features of Parrot is its advanced language parsing features which make implementing a new grammar almost trivial -- the Parrot Grammar Engine (PGE). A humorous, but practical example of using PGE can be found in this LOLCODE implementation.
Perl's looking a little long in the tooth these days -- there are so many more exciting languages out there, like PHP, Python and Ruby. But there's still an enormous wealth of programs being written and updated on CPAN, and Perl still excels at the text-based manipulation which it got famous for.
If Perl 6 ever comes out, that may be interesting, although I'm still unsure of the impact of all the syntax and keyword changes. Seems even more complex than before!
On the other hand, I just found out about the PAR-Packer tool, which allows you to easily convert any Perl program into an EXE file. Previously, the only easy method to my knowledge was the proprietary perl2exe tool from IndigoStar.
A useful place to check for the Win users among us who want to get their hands dirty with Parrot/Perl 6 without compiling:
