Ohm is a parser generator consisting of a library and a domain-specific language. You can use it to parse custom file formats or quickly build parsers, interpreters, and compilers for programming languages. The Ohm language is based on parsing expression grammars (PEGs), which are a formal way of describing syntax, similar to regular expressions and context-free grammars. The Ohm library provides a JavaScript interface (known as Ohm/JS) for creating parsers, interpreters, and more from the grammars you write.

For more information, see the GitHub project.