<div align="center"><a href="https://github.com/coignard/o2">
<picture>
<source srcset="https://github.com/coignard/o2/blob/main/assets/orca.png?raw=true">
<img src="assets/orca.png" alt="Orca" width="150">
</picture>
</a>
Rust port of the ORCΛ esoteric programming language and terminal livecoding environment
[](https://github.com/coignard/o2/actions)
[](https://github.com/coignard/o2/security/code-scanning)
[](https://docs.rs/o2-rs)
[](https://codecov.io/github/coignard/o2)
[](https://crates.io/crates/o2-rs)
[](LICENSE)
[](https://ko-fi.com/coignard)
</div>
## Install
To download the source code, build the O₂ binary, and install it in `$HOME/.cargo/bin` in one go run:
```bash
cargo install --locked --git https://github.com/coignard/o2
```
Or install via Homebrew:
```bash
brew install coignard/tap/o2
```
Alternatively, you can manually download the source code and build the O₂ binary with:
```bash
git clone https://github.com/coignard/o2
cd o2
cargo build --release
sudo cp target/release/o2 /usr/local/bin/
```
## Install as library
Run the following Cargo command in your project directory:
```bash
cargo add o2-rs
```
Or add the following line to your `Cargo.toml`:
```toml
o2-rs = "0.2.1"
```
## Extensions
O₂ extends the original ORCΛ operator set with one additional glyph.
The `_` character is valid in the length port of the MIDI (`:`) and Mono (` % `) operators. It creates a note with no scheduled Note Off.
## Test
```bash
cargo test
```
## Credits
O₂ is a Rust port of the [ORCΛ](https://github.com/hundredrabbits/Orca) esoteric programming language and livecoding environment, combining the best of the original JS and C implementations by [Hundred Rabbits](https://github.com/hundredrabbits) (Devine Lu Linvega & Rek Bell).
## License
The O₂ source code is © 2026 René Coignard and licensed under the [GNU General Public License v3.0 or later](LICENSE).
The `examples/` directory contains patch files from the [Orca-C](https://github.com/hundredrabbits/Orca-c) project, © 2017 Hundredrabbits, and are distributed under the [MIT License](examples/LICENSE).