A LALR(1) Parser Generator for JavaScript written in JavaScript
JS/CC is a parser generator for JavaScript/ECMAScript, which is entirely written in ECMAScript itself. It produces LALR(1) parsers with integrated lexical analyzers. JS/CC can run as a website or be invoked from a console, and runs on several platforms.
A multi-language port of Browserscope's user agent parser
ua-parser is a multi-language library for parsing User-Agent strings into structured data, such as browser, OS, and device information. Originally created for web analytics and user tracking, it supports a wide range of platforms and is available in JavaScript, Python, Java, and other languages. ua-parser is often used in server logs, analytics dashboards, and A/B testing systems to segment traffic.