NPG is a N
enerator. It's a small compiler of backtracking recursive descent parser
s that accepts grammars in a somehow extended BNF notation of arbitrary complexity (excluding indirect left recursive rules). It doesn't produce any file, it just compiles the grammar internally, ready to be used. A couple of examples are included: a VS-Cobol II and a Python
grammar (both far from complete).
s-exp syntax parser generator