ossia score

The software is an open‑source intermedia sequencer that lets creators arrange audio, video, and other media on a timeline while supporting a wide range of external protocols. It can play multichannel H.264 and HAP video, handle many audio formats, and communicate via OSC, MIDI, DMX, HTTP, serial, CoAP, MQTT, BLE and several other interfaces, enabling integration with IoT devices, gamepads, and creative‑coding environments.

It offers a mixed workflow that combines a traditional timeline with a nodal view, allowing users to switch between linear sequencing and modular graph editing. Conditional triggers, branching logic, and state‑machine‑like structures make it suitable for interactive performances and installations where external hardware or software can control any part of the score. Scripting is possible with embedded JavaScript, Faust audio processors, and a C++ API, while simple math expressions can be used for quick control.

The platform runs on macOS, is considered stable, and is designed for artists, sound designers, and developers who need precise, scriptable control over multimedia presentations and interactive scenarios.