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https://github.com/just-js/just
the only javascript runtime to hit no.1 on techempower :fire:
https://github.com/just-js/just
javascript linux runtime system-programming
Last synced: 1 day ago
JSON representation
the only javascript runtime to hit no.1 on techempower :fire:
- Host: GitHub
- URL: https://github.com/just-js/just
- Owner: just-js
- License: mit
- Created: 2020-07-17T03:07:34.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2023-11-17T12:28:54.000Z (about 1 year ago)
- Last Synced: 2025-01-17T11:03:44.086Z (9 days ago)
- Topics: javascript, linux, runtime, system-programming
- Language: JavaScript
- Homepage: https://just.billywhizz.io/
- Size: 337 KB
- Stars: 3,666
- Watchers: 62
- Forks: 126
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
Awesome Lists containing this project
- awesome-github-star - just - js | 3345 | (JavaScript)
- awesome-list - just - js | 1315 | (JavaScript)
README
# Just [](https://gitpod.io/#https://github.com/just-js/just)
## *** Attention ***
**17 Nov 2023**
This project is not being actively maintained in it's current state. please see [lo](https://github.com/just-js/lo) for a new, low-level JavaScript runtime i am working on. Very shortly this should be in a place where I will be able to "resurrect" the "just" project and base it on lo. Keep an eye out over coming weeks on [twitter](https://twitter.com/justjs14) or come join us on [discord](https://discord.gg/ZnNsBwaBKr) to discuss the new work. 🙏 🚀
## Build and Run
Currently working on modern linux (debian/ubuntu and alpine tested) on x86_64
```bash
# download and run the build script
sh -c "$(curl -sSL https://raw.githubusercontent.com/just-js/just/current/install.sh)"
# install just binary to /usr/local/bin
make -C just install
# export the just home directory
export JUST_HOME=$(pwd)/just
export JUST_TARGET=$JUST_HOME
# if you don't want to install, add JUST_HOME to SPATH
export PATH=$PATH:$JUST_HOME
# run a shell
just
```
## Create a new Application
```bash
# initialise a new application in the hello directory
just init hello
cd hello
# build hello app
just build hello.js --clean --static
./hello
```
## Command Line Options
### Run a Just shell/repl
```bash
just
```
### Pipe a script to stdin
```bash
cat hello.js | just --
```
### Eval some Javascript passed as an argument
```bash
just eval "just.print(just.memoryUsage().rss)"
```
### Run a script
```bash
just hello.js
```
### Initialise a new project and build it
```bash
just init hello
cd hello
just build
```
### Clean a built project
```bash
just clean
```
## Documentation
Coming soon...
## Philosophy/Goals
- small, secure, robust and performant js runtime for linux
- 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
- secure 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