rr

RR - Railroad Diagram Generator

RR is a generator of syntax diagrams, also known as railroad diagrams. It is a self-contained tool with both a browser-based GUI and a batch mode.

Besides generating diagrams from EBNF rules, RR also can perform some grammar transformation, e.g. factorization and elimination of direct recursion. To some extent this transforms BNF to EBNF, yielding more compact diagrams.