JS/CC is a LALR(1) parser generator for JavaScript/ECMAScript, with the feature that it was itself entirely written in JavaScript. The JS/CC parser generator is based on the concepts of the lex/yacc behavior, but unions both a lexical analyzer generator for matching the tokens of a language, and a LALR(1) parser generator for parsing the language structure as defined using a Backus–Naur form-based meta language.The characteristic, that JS/CC is capable to compile and run a complete parser from a grammar definition within a web browser makes it very useful for educational purposes. JS/CC can even be executed via command-line on Microsoft Windows systems using the Windows Script Host or JScript.NET executable to do the job. JS/CC was released as open source software under the Artistic License.