# moonbitlang/core
[](https://github.com/moonbitlang/core/actions/workflows/stable-check.yml) [](https://coveralls.io/github/moonbitlang/core?branch=main)
[](https://mooncakes.io/docs/moonbitlang/core)
moonbitlang/core is the standard library of the [MoonBit language](https://www.moonbitlang.com/). It is released alongside the compiler. You can view the documentation for the latest official release at . This repository serves as the development repository.
## Architecture at a glance
Almost every package in this repository sits on top of `builtin`, which is
available in every MoonBit program without an import (`builtin` itself
bootstraps on the tiny `abort` package). `prelude` is opened automatically
and re-exports the commonly used names from `builtin` plus a few companions
(`Debug`, `BigInt`, `Ref`, `Lazy`, test assertions, …). Everything else is an
ordinary package imported as `moonbitlang/core/` and used via `@`:
```mermaid
graph BT
builtin["builtin (implicitly available, no import)
Array · FixedArray · Map · String · Bytes · views
Iter · StringBuilder · Json
traits: Eq · Compare · Hash · Show · ToJson · Default"]
prelude["prelude — auto-opened re-exports
from builtin, debug, test, bigint, …"] --> builtin
values["value types
bool · byte · char · unit · option · result
error · ref · tuple · cmp · range · lazy"] --> builtin
numbers["numerics
int · uint · int16 · uint16 · int64 · uint64
double · float · bigint · v128 · math"] --> builtin
text["text & binary
string · bytes · buffer · encoding/*
lexbuf"] --> builtin
mut["mutable collections
array · hashmap · hashset · deque · queue
priority_queue · set · sorted_map · sorted_set"] --> builtin
imm["immutable collections
list · lazy_list · immut/vector
immut/hashmap · immut/sorted_map · …"] --> builtin
tools["algorithms & tooling
json · diff · random · quickcheck · argparse
bench · test · debug · env"] --> builtin
```
## Current status
It is experimental and under active development. At this early stage, our primary focus is on enhancing the functionality of `moonbitlang/core`.
⚠️**The API is subject to change.**
## Contributing
We are actively developing moonbitlang/core and appreciate your help!
To contribute, please read the contribution guidelines at [CONTRIBUTING.md](./CONTRIBUTING.md).
### Being a collaborator
Note we regularly evaluate external contributions and invite active contributors to join us as collaborators, thank you!
To keep the contributors manageable, we will revoke commit rights if external collaborators are not active for over 6 months.