Canopy

Canopy is a parser compiler for parsing expression grammars (PEG) targeting JavaScript, Java, Python, and Ruby. Version 0.4.1 is the latest stable release; the project appears to be in maintenance mode with no recent activity. It generates standalone parsers with no runtime dependencies, making it lightweight. Unlike PEG.js or Nearley, Canopy offers multi-language code generation from a single grammar file.