Happy
A dyslexic acronym for "A Yacc-like Haskell Parser generator".
An LALR1 grammar parser generator for Haskell. Happy is written in Haskell, uses a parser generated by itself, and can be compiled using ghc, hbc or gofer. Happy uses an implementation of monadic IO built on top of stream IO, but this should change when the Haskell 1.3 standard has been implemented.
Version: 0.9 (1996-02-28).
Happy is covered by the General Public License.
http://dcs.gla.ac.uk/fp/software/happy.html.