Just is a very small v8 JavaScript runtime for Linux only.
Just is no longer actively maintained. The developer is working on Io, a low-level JavaScript runtime.
This is free and open source software.
Goals of the project were:
- Small, secure, robust and performant js runtime.
- Small codebase. easy to understand and hack.
- Very simple layer on top of system calls, v8 and c/c++ standard libraries.
- Minimal use of classes/function templates and OO – “c” in JavaScript.
- Favour return codes over exceptions.
- Platform for building system software on linux in JavaScript.
- As close to native performance as possible.
- Aecure by default.
- Avoid abstraction as much as possible. abstractions can be built in userland.
- commonjs modules, no support for ES modules.
- non-async by default – can do blocking calls and not use the event loop.
- Event loop in JS-land. full control over epoll api.
- Small standard library – leave as much to userland as possible. focus on primitives needed to build higher level abstractions.
- Useful as a teaching/learning platform for linux system programming and learning more about JavaScript and v8 internals.
- Small number of source files.
- Minimal dependencies – g++ and make only.
- Keep LOC as small as possible < 5k.
- Allocate as little as possible on v8 heap.
Website: just.billywhizz.io
Support: GitHub Code Repository
Developer: Andrew Johnston
License: MIT License
Just is written in JavaScript and C++. Learn JavaScript with our recommended free books and free tutorials. Learn C++ with our recommended free books and free tutorials.
Related Software
| JavaScript Runtime Environments | |
|---|---|
| Node.js | Hugely popular cross-platform JavaScript run-time environment |
| Bun | Fast JavaScript runtime designed as a drop-in replacement for Node.js. |
| Deno | Simple, modern and secure runtime for JavaScript and TypeScript that uses V8 |
| WasmEdge | High-performance, and extensible WebAssembly runtime |
| txiki.js | Small and powerful JavaScript runtime |
| JerryScript | JavaScript engine for the Internet of Things |
| Window.js | JavaScript runtime for desktop graphics programming |
| Blueboat | Multi-tenant serverless JavaScript runtime |
| lo | Successor project to Just |
| Just | Very small v8 JavaScript runtime |
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