browsers as old as IE6. Futhark: The ECMAScript engine of the Opera web browser versions 9.50 to 10.10. InScript: An obsolete proprietary library used for iCab 2 and 3. JScript: The engine that is used in Internet Explorer for versions up to IE9, and one component of the MSHTML (Trident) browser engine. Jint: Javascript interpreter with integrated engine for .NET KJS: The engine used in Konqueror, and one component of KHTML, a predecessor to JavaScriptCore. Linear B: The ECMAScript engine of the Opera web browser versions 7.0 to 9.50, exclusive. Narcissus: JavaScript implemented in JavaScript (a meta-circular evaluator), intended to run in another JavaScript engine, of theoretical and educational nature only. JS-Interpreter A lightweight JavaScript interpreter implemented in JavaScript with step-by-step execution. QtScript: Originally developed by Trolltech, now owned by The Qt Company. It provides QObject integration with JavaScriptCore. V4 (QJSEngine): Qt's newer ECMAScript engine, powering QML and QtQuick. ES6-compliant and under active development at The Qt Company. V4 is JIT compiled. Rhino: One of several JavaScript engines from Mozilla, using the Java platform. YAJI: An ECMAScript engine based on the FESI implementation by Jean-Marc Lugrin in 1999, using the Java platform, currently being developed to support the latest standards (ECMAScript spec. 262, v5.1). Microvium: JavaScript engine for microcontrollers, supporting a restricted subset of the ECMAScript specification, using less than 16kB of flash memory and 64B of RAM while idle. Duktape: A small footprint, easily embeddable Ecmascript E5/E5.1 engine. XS JavaScript Engine: An ECMAScript 2020-compliant engine for microcontrollers with limited resources. XS is maintained by Moddable as part of the Moddable SDK and was formerly part of the Kinoma Platform. Jsish: An ES5.1 subset interpreter with builtin SQLite, JSON, WebSocket, and ZVFS support. Websocket.js: An embeddable Javascript engine with HTTP/Websocket support. Espruino: A very small footprint interpreter specifically for microcontrollers. Can run in less than 8 kB of RAM by executing from source (rather than bytecode). MuJS: A lightweight ECMAScript interpreter library, designed for embedding in other software to extend them with scripting capabilities. Originally developed for MuPDF. mJS: Restricted JavaScript engine. Used for Internet of Things (IoT). Tiny-JS: A minimal JavaScript interpreter written in C++. JerryScript: A lightweight JavaScript engine by Samsung for microcontrollers with less than 64 KB RAM. njs: A lightweight JavaScript interpreter optimized for web server scripting and fastest VM context creation; used in nginx. QuickJS: A lightweight ECMAScript 6 interpreter by Fabrice Bellard and Charlie