GitHub - ivankra/javascript-zoo: JavaScript engines zoo

V8

C++ JavaScript engine of Chrome, Node.js etc. ESnext 2008- 1.3M BSD-3 SpiderMonkey

C++ JavaScript engine of Firefox. ESnext 1996- 1.0M MPL-2.0 JavaScriptCore

C++ JavaScript engine of Safari/WebKit. ESnext 2001- 770K LGPL-2.0 LibJS

C++ JavaScript engine of Ladybird browser and SerenityOS. ESnext 2020- 73K BSD-2 Hermes

C++ JavaScript engine from Facebook optimized for running React Native mobile apps. ES2023 2019- 170K MIT QuickJS

C Lightweight embeddable JavaScript engine by Fabrice Bellard and Charlie Gordon. ES2023 2019- 74K MIT ChakraCore

C++ JavaScript engine of Microsoft Edge Legacy. ES2019 2015-2021 780K MIT JerryScript

C Lightweight JavaScript engine for microcontrollers. ES2022 2014-2024 109K Apache-2.0 Duktape

C Embeddable Javascript engine with a focus on portability and compact footprint. ES5 2013- 73K MIT MicroQuickJS

C JavaScript engine targetted at embedded systems. ES5 2025- 24K MIT QuickJS-NG

C Community-oriented fork of QuickJS. ES2023 2023- 74K MIT njs

C Lightweight embeddable JavaScript engine for use in nginx. ES6 2015- 59K BSD-2 XS

C Lightweight engine for microcontrollers/IoT by Kinoma/Marvell. ESnext 2002- 89K Apache/LGPL cesanta/v7

C JavaScript engine for microcontrollers. ES5 2013-2017 25K GPL-2.0 PrimJS

C++ QuickJS-based engine from ByteDance for their cross-platform mobile apps framework Lynx. ES2019 2024- 292K Apache-2.0 MuJS

C Embeddable JavaScript engine from MuPDF. ES5 2013- 18K ISC 42tiny-js

C++ Fork of tiny-js with more features. no 2010-2014 9.2K MIT tiny-js

C++ Primitive interpreter for a limited subset of JavaScript. no 2009-2012 2.4K MIT iv / lv5

C++ JIT-enabled ES5 engine in C++. ES5 2009-2015 70K BSD-2 Mocha

C++ The very first JavaScript engine that defined early JavaScript language (JS1.0/1.1), shipped in Netscape Navigator 2.0-3.0. JS1.1 1995-1996 14K Proprietary Escargot

C++ Lightweight JavaScript engine by Samsung for mid-range devices like phones/TVs. ESnext 2016- 116K LGPL-2.1 QV4 / QJSEngine

C++ JavaScript engine of Qt's QML framework (QJSEngine). ES2016 2012- 50K Qt/GPL/LGPL Tamarin

C++ JavaScript engine of Adobe Flash Player 9+. ES4 2006-2013 193K MPL-2.0 yrm006/miniscript

C Primitive unfinished interpreter. no 2018 2.0K Missing Flathead

C Buggy unfinished interpreter. no 2012-2017 7.1K MIT QuickJIT

C QuickJS fork that JIT-translates bytecode using TCC. ES2019 2023 87K MIT/LGPL-2.1+ jsish

C Buggy unfinished interpreter. no 2020-2022 51K MIT KJS

C++ Original JavaScript engine of KDE's Konqueror browser. ES5 1998-2023 42K LGPL-2.1 Epimetheus

C++ Netscape's experimental "JavaScript 2.0" implementation towards ES4 proposal. ES4 2000-2006 42K MPL/GPL/LGPL SophonJS

C Small footprint embedded ES5 engine. ES5 2015 23K BSD-3 malbrain

C JavaScript interpreter with a built-in NO-SQL database. 2016-2020 12K Missing quad-wheel

C Buggy unfinished interpreter. no 2010 7.9K MIT AWeb

C JavaScript engine of AWeb, a web browser for Amiga. ES3 2002-2007 23K Custom Quanta

C++ Buggy unfinished interpreter. no 2025- 42K MPL-2.0 stackluca/v3

C Toy JavaScript interpreter. 2016 4.3K MIT Voyager

C Web browser for Amiga with own JavaScript implementation. ES3 199x-2002 12K GPL-3.0 DscriptCPP

C++ DMDScript version implemented in C++. ES3 2000 44K BSL-1.0 ixlib

C++ C++ utility library with a rudimentary JavaScript interpreter. 2005 3.8K LGPL-2.0 CRIScript

C++ Lightweight ES3 interpreter for game engines. ES3 2008 37K Custom NGS

C An independent implementation of JavaScript from late 1990s. JS1.4 1998-1999 36K LGPL-2.0 QSA

C++ Qt 3's JavaScript engine: Qt Script for Applications. ES4 2002-2007 GPL-2.0 Ejscript

C Embeddable JavaScript engine. ES4 2003-2014 107K GPL-2.0 Carakan
(archive.org) C++ JavaScript engine of Opera 10.50 – 12.18. ES5 2010-2013 125K Proprietary ChowJS
(mp2.dk) C QuickJS-based optimizing AOT compiler to native code for game developers. ES2020 2021 Proprietary Edbrowse
(edbrowse.org) C Edbrowse CLI browser had own small JavaScript engine until v2.2.10 (2006). 2004-2006 2.3K GPL JScript
(microsoft.com) C++ JavaScript engine of Internet Explorer 3.0 – 8.0. ES3 1996-2011 Proprietary JScript9 / Chakra C++ JavaScript engine of Internet Explorer 9.0 – 11.0. ES6 2009-2013 Proprietary Links
(twibright.com) C Links browser had a basic JavaScript engine until version 2.1pre28. ES3 2002-2007 14K GPL-2.0+ Opera
(opera.com) C++ Early JavaScript engines of Opera browser: Linear A, Linear B, Futhark. ES3 1997-2009 Proprietary QtScript
(qt.io) C++ Qt 4.3-5.x's JavaScript engine based on JavaScriptCore. 2007-2023 GPL/LGPL ScriptEase
(brent‑noorda.com) C Scripting engine of Nombas ScriptEase, most famous for being used by James Webb Space Telescope. ES3 199x-2004 Proprietary SEE
(archive.org) C Simple ECMAScript Engine. ES3, JS1.5 2003-2009 34K BSD-3 Jint

C# JavaScript interpreter for .NET. ESnext 2013- 53K BSD-2 Jurassic

C# JavaScript engine for .NET, a compiler to .NET IL. ES5, ES6 2010- 35K MIT IronJS

C# ES3 implementation for .NET, built on top of .NET DLR (Dynamic Language Runtime). ES3 2010-2013 13K Apache-2.0 NiL.JS

C# JavaScript interpreter for .NET. ES6 2013- 42K BSD-3 Topaz

C# Multithreaded JavaScript engine for .NET. ES6 2021- 22K MIT Yantra

C# JavaScript engine for .NET. Tree walking interpreter + expression compiler to .NET IL. ES6 2020- 55K Apache-2.0 MuscalietJS

C# JavaScript interpreter / compiler to CIL. Abandoned prototype for a paper. 2014 50K BSD-3 JANET
(archive.org) C# JavaScript implementation for .NET by Steve Newman (of Writely). JS1.4 2001 GPL JScript .NET
(microsoft.com) C# Old Microsoft's JavaScript engine for .NET Framework 1.0-4.x from early 2000s / ES4 era. ES4 2000-2010 Proprietary Higgs

D JIT compiler for JavaScript targetting x86-64 platforms. ES5 2012-2015 40K BSD-3 DMDScript

D ECMAScript implementation by Digital Mars written in D. ES3 2002- 18K BSL-1.0 otto

Go JavaScript engine in pure Go. ES5 2012- 26K MIT goja

Go JavaScript engine in pure Go. Fully ES5 compliant, partially ES6+. ES2023 2016- 46K MIT Hako

Go Embeddable WebAssembly-sandboxed PrimJS fork. ES2019 2025- 18K Apache-2.0 fastschema/qjs

Go JavaScript in Go with QuickJS and Wazero. ES2023 2025- 14K MIT Sobek

Go Grafana's fork of goja engine. ES2023 2024- 47K MIT ModerncQuickJS

Go QuickJS transpiled to pure Go. ES2023 2024- 167K BSD-3/MIT hjs
(haskell.org) Haskell Haskell JavaScript parser and interpreter. ES3, JS1.5 2007 2.2K BSD-3 Rhino

Java JavaScript engine from Mozilla for the Java platform, bundled with JDK 6-7. ES2023 1997- 84K MPL-2.0 GraalJS

Java High-performance JavaScript engine for JVM/GraalVM. ESnext 2018- 192K GFTC/UPL-1.0 Nashorn

Java JavaScript engine of JDK 8-14 (2014-2020), based on invokedynamic JVM opcode. ES6 2011- 89K GPL-2.0 topchetoeu

Java ES5 interpreter written in Java. ES5 2023-2025 16K MIT LebJS

Java Unfinished JavaScript engine written in Java. no 2021- 14K Apache-2.0 YAJI

Java Fork of FESI interpreter with ES5 support. ES5 2011-2012 41K LGPL-3.0 FESI
(archive.org) Java JavaScript interpreter written in Java. ES1 1998-2003 24K LGPL-2.0+ Porffor

JavaScript Optimizing AOT compiler for JavaScript/TypeScript targetting WebAssembly and native binaries. 2023- 28K MIT JS-Interpreter

JavaScript Sandboxed ES5 interpreter in JavaScript. ES5 2013- 5.0K Apache-2.0 bramblex/jsjs

TypeScript Toy metacircular JavaScript interpreter. 2018 662 Missing ts2c

TypeScript JavaScript/TypeScript to C transpiler. ES3 2016- 9.5K ISC sablejs

JavaScript Closed-source bytecode-based sandboxed ES5 interpreter in JavaScript. ES5 2020-2022 Custom engine262

TypeScript An implementation of ECMA-262 in JavaScript aiming for 100% spec compliance, fast prototyping, validating new spec versions and test262. ESnext 2018- 39K MIT Narcissus

JavaScript Metacircular JavaScript interpreter, was used for prototyping new language features in ES6. ES5 2007-2012 6.3K MPL/GPL/LGPL eval5

TypeScript ES5 interpreter written in TypeScript. ES5 2019- 1.7K MIT EchoJS

JavaScript AOT compiler and runtime for ES6. ES6 2012-2023 39K MIT sval

TypeScript Metacircular JavaScript interpreter. ES2017 2018- 2.1K MIT Tachyon

JavaScript Metacircular VM for JavaScript (ES5) written in JavaScript. ES5 2010-2012 58K BSD-3 jscomp

TypeScript AOT compiler targetting native code via C++. ES5 2015-2016 20K Apache-2.0 SandboxJS

TypeScript Interpreter for a limited subset of ES6 for sandboxing untrusted code, preventing access to non-whitelisted functions/prototypes. ES6 2019- 4.2K MIT metaes

TypeScript Metacircular JavaScript interpreter. ES2017 2015-2022 2.8K MIT Tessel Colony

JavaScript JavaScript to Lua compiler. ES5 2013-2015 1.8K Apache/MIT Continuum

JavaScript ES6 interpreter written in ES3. ES6 2012-2014 22K MIT Reeva

Kotlin JavaScript interpreter for JVM written in Kotlin. 2020- 26K BSD-2 Charon
(bitbucket.org) Limbo JavaScript engine of Inferno OS (Plan 9's successor)'s Charon browser. 2006 7.3K MIT CL-JavaScript

Lisp JavaScript to Common Lisp compiler. ES3 2009-2012 3.4K MIT Ejacs

Lisp Toy JavaScript interpreter for Emacs, inspired by Narcissus. ES1 2008 9.9K GPL-2.0 castl

Lua Self-hosting JavaScript to Lua compiler with a runtime library and eval(). ES5 2014-2017 6.4K LGPL-3.0+ Bali

Nim Unfinished JavaScript engine written in Nim. no 2024- 13K BSD-3 BESEN

Pascal JIT-enabled ES5 engine written in Object Pascal. ES5 2009-2020 57K LGPL-2.1 DMonkey
(archive.org) Pascal ECMAScript engine written in Delphi. 2005 55K BSD-3 je-perl
(metacpan.org) Perl JavaScript engine in pure Perl. ES3 2007-2014 11K Artistic/GPL Js2Py

Python JavaScript interpreter written in Python. ES5 2014-2022 69K MIT rpython-langjs

Python JavaScript interpreter for PyPy. ES3 2009-2013 7.2K Missing twostroke

Ruby JavaScript interpreter written in Ruby. ES3 2011-2012 4.7K MIT Boa

Rust Embeddable Javascript engine written in Rust. ESnext 2018- 141K MIT/Unlicense Nova

Rust Experimental JavaScript engine written in Rust with a cache-friendly data-oriented design. ES6+ 2022- 102K MPL-2.0 Brimstone

Rust Javascript engine written in Rust, with nearly complete ES2025 support. ESnext 2022- 74K MIT Jawsm

Rust JavaScript to WebAssembly compiler. 2024- 12K Apache-2.0 Rapidus

Rust JavaScript engine written in Rust, aiming at ES5. ES5 2018-2021 11K MIT Starlight

Rust JavaScript engine written in Rust. no 2021 28K MPL-2.0 echosoar/jsi

Rust JavaScript interpreter written in Rust with QuickJS-inspired bytecode. no 2022- 5.9K MIT DelSkayn/toyjs

Rust Toy JavaScript interpreter written in Rust. 2020-2024 19K Missing Yavashark

Rust JavaScript/TypeScript engine written in Rust. 2024- 177K MIT Kiesel

Zig JavaScript engine written in Zig. ESnext 2023- 59K MIT