With MJD's blessing, I've released HOP::Stream, HOP::Lexer and HOP::Parser to the CPAN (where the "HOP" stands for "Higher Order Perl"). The lexer and parser should show up soon but the stream module is already there.
Unfortunately, for the most part, the documentation for the modules is MJD's book. They could use a lot of work, particularly the parser. However, there are some cool new subparsers build into the parser module and it has over 120 tests so far.
Patches (particularly with tests) and kibitzing quite welcome.
Update: hey, this is my 666th journal entry here. Maybe that's a sign.