Rust port of the ORCΛ esoteric programming language and terminal livecoding environment

To download the source code, build the O₂ binary, and install it in $HOME/.cargo/bin in one go run:

cargo install --locked --git https://github.com/coignard/o2

Or install via Homebrew:

brew install coignard/tap/o2

Alternatively, you can manually download the source code and build the O₂ binary with:

git clone https://github.com/coignard/o2
cd o2
cargo build --release
sudo cp target/release/o2 /usr/local/bin/

Run the following Cargo command in your project directory:

cargo add o2-rs

Or add the following line to your Cargo.toml:

o2-rs = "0.2.5"

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.

cargo test

O₂ is a Rust port of the ORCΛ esoteric programming language and livecoding environment, combining the best of the original JS and C implementations by Hundred Rabbits (Devine Lu Linvega & Rek Bell).

The O₂ source code is © 2026 René Coignard and licensed under the GNU General Public License v3.0 or later.

The examples/ directory contains patch files from the Orca-C project, © 2017 Hundredrabbits, and are distributed under the MIT License.