(that is: if you can't do Lisp-like metaprogramming, the next best thing is doing DSL metaprogramming. :)

Parsers

• Parse::RecDescent — very slow (like O(n³) slow), but flexible
• Regexp::Grammers — perl 5.10 only, but supposedly lots better than Parse::RecDescent
• Parse::Yapp — faster than Parse::RecDescent, but less flexible
• byacc-perl — a patch to the standard byacc program that makes it output Perl code (faster even than Yapp)
• Parse::YALALR

Lexers

• HOP::Lexer
• Parse::Lex [generates .pl code]
• Parse::Flex [generates .c code]
• you can glue flex onto Perl via xs