Open-source alternatives to Duktape

mQuickjs is a compact JavaScript engine designed for memory-constrained devices, such as microcontrollers, requiring as little as 10 KB of RAM and 100 KB of ROM. It achieves this through a fixed-buffer memory allocation scheme that avoids system heap usage, a compacting tracing garbage collector that eliminates fragmentation, and a ROM-embedded standard library that reduces both memory footprint and startup time. The engine compiles JavaScript source into portable bytecode that can be stored in persistent memory and executed without reparsing, and it emulates IEEE 754 floating-point arithmetic

mruby is a lightweight Ruby interpreter designed to be embedded into C applications. It compiles Ruby source code into a compact, platform-independent bytecode that executes on a register-based virtual machine, and exposes a stable C API for host programs to initialize the interpreter, load bytecode, and invoke Ruby methods at runtime. The interpreter distinguishes itself through a tightly coupled parser and compiler that performs lexical analysis, syntax parsing, and bytecode generation in a single pass without constructing an intermediate AST, minimizing memory overhead. It also includes a

Janet is a Lisp-based dynamic programming language featuring a register-based bytecode virtual machine and an embeddable scripting engine. It functions as a fiber-based concurrency runtime and includes a parsing engine based on Parsing Expression Grammars. The project is distinguished by its ability to be integrated into C or C++ applications via a minimal header interface. It utilizes a Lisp-style macro system for compile-time code transformation and employs prototype-based table inheritance for object-oriented behavior. The runtime covers a broad set of capabilities, including asynchronous

Gopher-lua is a complete implementation of the Lua language and its standard libraries written natively in Go. It serves as an embedded scripting engine and virtual machine that allows Go applications to execute Lua scripts and exchange data between the host and the script environment. The project provides a bytecode compiler to transform source code into a binary format for faster execution. It enables deep integration between the two languages by allowing the registration of native Go functions to be called from scripts, and the invocation of script functions directly from Go. The engine c

Sol2 is a C++ Lua binding library that serves as a language interoperability layer for integrating Lua scripts into C++ applications. It acts as a scripting wrapper and API toolkit, enabling the execution of Lua code and the management of shared state within a native C++ environment. The library focuses on automated function and type mapping to bridge native C++ classes and complex data types with the Lua scripting engine. It provides mechanisms for bidirectional data exchange, allowing compiled logic and variables to be synchronized between the host application and the script runtime. The s

ChakraCore is an embedded JavaScript engine designed to be integrated as a library within a host application. Its primary purpose is to provide a programmable scripting layer and a lightweight runtime environment for executing JavaScript code and managing state via a programmatic interface. The project focuses on bridging high-level scripting with low-level system calls through a C API. This allows developers to implement custom scripting engines and embed JavaScript execution directly into applications to enable task automation and functional extensions. The engine utilizes a bytecode-based

Wren is an embeddable, class-based scripting language and bytecode interpreter. It provides a dependency-free virtual machine designed for integrating dynamic script execution into host applications via a C API. The language is centered on a modern object-oriented model featuring inheritance, method overloading, and first-class functions. It utilizes a concurrent fiber runtime to manage lightweight, cooperatively scheduled execution paths without relying on operating system threads. The project includes a comprehensive suite of object-oriented primitives, closure-based state capture, and a m

Unreal.js is a JavaScript runtime and scripting layer for Unreal Engine that embeds the V8 engine to implement game logic and manage application state. It provides a bridge for writing high-level application behavior and actor control without modifying the core engine source code, as well as a framework for extending the Unreal Engine editor with custom interface elements. The project distinguishes itself through a V8-based integration that supports real-time code reloading and live iteration, allowing scripts to be updated without restarting the application. It includes a bidirectional commu

LuaViewSDK is a cross-platform UI engine and framework that uses a Lua-based scripting engine to render native user interfaces across multiple mobile operating systems. It functions as a dynamic UI orchestrator, separating interface logic from the underlying operating system to allow for the creation of native views driven by scripts. The system features a bidirectional native scripting bridge for exchanging data and triggering functions between the script runtime and native platform APIs. It also includes a Lua game runtime capable of executing interactive graphics and lightweight games thro

PythonNet is a runtime integration bridge that enables Python code to call .NET assemblies and functions within the Common Language Runtime. It serves as a set of bindings for accessing the .NET framework and its libraries from a Python environment, facilitating cross-language runtime interoperability. The project provides a mechanism for embedding a Python scripting engine directly within .NET applications. This allows for the creation of an application scripting layer where Python code is executed dynamically to provide customization and automation for the host environment. The bridge supp

V8 is a high-performance JavaScript and WebAssembly engine designed to compile and execute code within host applications. It functions as an embeddable scripting engine and just-in-time compiler, providing a portable library for integrating dynamic script execution into native software environments. The engine incorporates a WebAssembly runtime to execute compiled binary code for a stack-based virtual machine at near-native speeds. It enables native application scripting by allowing a JavaScript execution environment to be embedded directly into a native program to handle dynamic logic. The

esm is an ECMAScript module loader and JavaScript module path resolver. It functions as a runtime system that executes standard JavaScript modules without requiring a separate build or bundling process. The project provides a compatibility bridge for CommonJS interoperability, wrapping CommonJS exports into synthetic modules to allow imports and exports between different module systems. It includes a dynamic module cache that stores resolved instances in memory to prevent redundant file system reads and repeated execution. The system handles runtime path resolution and file extension detecti

Gosub-engine is an HTML5 browser engine and web rendering pipeline that parses HTML5 and CSS3 to compute layout and render web content to pixels. It functions as a JavaScript runtime environment with a virtual machine and event loop for handling dynamic logic and asynchronous tasks. The system also includes a web storage manager for persisting cookies, local storage, and session storage. The project features a headless browser renderer capable of generating page images or extracting plain text without a visible window. It supports cross-platform graphics rendering through pluggable CPU and GP

rusty_v8 is a Rust wrapper for the V8 JavaScript engine that allows for the embedding of a JavaScript runtime into native applications. It provides core components for managing engine bindings, memory allocation, sandboxed isolates, and the execution of WebAssembly modules. The project features a native host function bridge to map Rust functions to JavaScript objects and a dedicated memory allocator to manage thread-safe allocation and heap pressure. It includes a system for compiling and executing binary WebAssembly modules within the hosted native environment. The runtime covers capabiliti

Jint is a JavaScript interpreter for the .NET ecosystem that executes code without requiring a browser or Node.js environment. It is an ECMAScript compliant engine that provides a sandboxed scripting runtime with configurable limits on memory and time to run untrusted code. The engine features a native object bridge that exposes .NET classes and methods to JavaScript scripts for bidirectional data exchange. To reduce overhead during repeated executions, it utilizes a precompiled script cache to store parsed JavaScript in memory. The project covers asynchronous script execution and promise ha

Otto is a Go implementation of a JavaScript interpreter and embedded scripting engine. It provides a runtime environment for executing JavaScript code within native applications and includes a parser that converts source code into an abstract syntax tree for analysis and processing. The project enables the creation of custom scripting interfaces by binding native Go functions into the JavaScript global scope. It also includes a utility to translate JavaScript regular expression patterns into compatible formats for other programming languages. The engine supports safe script sandboxing throug

MicroPython is a lean implementation of Python 3 optimized to run on microcontrollers and other resource-constrained systems. It serves as a cross-platform embedded runtime and hardware abstraction layer, providing a firmware framework that maps high-level software commands to specific microcontroller registers across diverse processor architectures. The project functions as an embedded language interpreter that enables rapid prototyping on hardware through an interactive read-eval-print loop. It supports a wide range of target environments, including ARM, ESP32, STM32, RISC-V, and WebAssembl

Swift is a general purpose, compiled systems programming language designed for building high-performance software. It is a strongly typed language that focuses on memory safety and type safety to prevent runtime errors. The language is designed for native code integration, allowing it to interoperate with C and Objective-C libraries to leverage existing system functions and high-performance APIs. The project covers broad capabilities in type-safe application development and cross-platform toolchain engineering. It includes infrastructure for automated language validation, compiler performanc

Goja is a JavaScript engine and ECMAScript compliant interpreter implemented entirely in Go. It serves as an embedded scripting engine that allows Go applications to execute JavaScript code and integrate a programmable scripting layer without relying on Cgo or external native dependencies. The project functions as a bridge between Go and JavaScript, enabling bidirectional data exchange and function invocation. It allows Go hosts to expose native structs, slices, and maps as JavaScript objects and arrays, while providing mechanisms to export script values and functions back into native Go type

NoahGameFrame is a distributed game server framework designed for real-time multiplayer games. It utilizes an actor model backend to manage game state and logic through an asynchronous, event-driven system that distributes workloads across multiple CPUs. The framework features a scriptable server environment that integrates external scripting languages, allowing for updates to game behavior and mechanics without restarting the server. It also employs a plugin-based architecture with an interface-oriented design to enable the addition of custom application logic and modular engine extensions.

Hermes is a mobile-optimized JavaScript runtime and engine designed for React Native. It functions as an ahead-of-time bytecode compiler that converts JavaScript source code into a dense binary format during the build process to eliminate the need for parsing and compilation at runtime. The engine features a baseline JIT compiler that generates native machine code for frequently called functions to improve performance after the initial launch. It also includes a mobile-optimized garbage collector that precisely identifies reachable objects to minimize memory overhead and pause times on resour

Flecs is a high-performance entity component system framework and data-oriented programming library. It serves as a simulation engine core and game engine architecture tool, decoupling state from behavior by separating entities, components, and systems. The framework features a runtime reflection layer for dynamic data inspection and a built-in scripting system for defining entity behavior without recompilation. It also includes a network interface and REST API for remote simulation administration and state querying. The library covers a broad surface of simulation capabilities, including ar

Luau is a high-performance programming language evolved from Lua 5.1. It consists of a bytecode virtual machine, an embeddable scripting engine, and a static code analyzer designed to provide a secure, sandboxed execution environment for host applications. The project is distinguished by its gradual typing system, which combines automatic type inference with optional manual annotations to detect bugs without requiring full static typing. It also features native vector mathematics for high-performance operations and a specialized debugging system that uses bytecode patching to minimize executi

Embedded JavaScript engine for C/C++

Boost.org python module

Embedded Scripting Language Designed for C++

pybind11 is a header-only C++ binding library that exposes C++ functions and classes as Python modules. It serves as a language bridge, mapping native types, inheritance hierarchies, and lambda functions into compatible Python objects to enable high-performance native code execution. The library includes specialized integration for NumPy arrays, utilizing buffer protocols to bind native C++ data without copying memory. It provides a toolkit for mapping C++ standard library data structures and smart pointers into the Python environment while maintaining cross-language memory management. The p