Licenses
Last updated: March 6, 2026
LoonBox Licensing
LoonBox uses a permissive ecosystem model: the application itself is copyleft, but themes and plugins you build are yours to license however you choose.
Application License
LoonBox source code is licensed under the GNU Affero General Public License v3.0 (AGPL-3.0).
This means:
- You can view, modify, and redistribute the source code
- If you modify LoonBox and distribute it or run it as a network service, you must share your modifications under the same license
- Full license text: LICENSE
Ecosystem Carve-Out
Feathers (themes) and extensions (plugins) that interact with LoonBox solely through the documented public APIs may be distributed under any license, including proprietary licenses. The AGPL-3.0 does not extend to these works.
This means you can build and sell commercial feathers and extensions without open-sourcing them.
Contributor License Agreement
Contributors to LoonBox sign a CLA that:
- Lets you retain copyright ownership of your contributions
- Grants MPLS LLC a license to use, modify, and relicense contributions
- Full text: CLA.md
Rust Crates
| Crate | Purpose | License |
|---|---|---|
| symphonia | Audio decoding (MP3, FLAC, OGG, WAV, AAC) | MPL-2.0 |
| cpal | Cross-platform audio output | Apache-2.0 |
| lofty | Audio metadata reading/writing | Apache-2.0 / MIT |
| mlua | Lua scripting engine for extensions | MIT |
| adblock | Brave adblock engine for embedded browser | MPL-2.0 |
| rqbit | BitTorrent client for Tremolo (planned) | Apache-2.0 |
| tokio | Async runtime (network layer only) | MIT |
| serde | Serialization | Apache-2.0 / MIT |
| flutter_rust_bridge | Dart-Rust FFI bridge | MIT |
Flutter / Dart Packages
| Package | Purpose | License |
|---|---|---|
| flutter | UI framework | BSD-3-Clause |
| flutter_riverpod | State management | MIT |
| drift | SQLite ORM / database | MIT |
| webview_windows | Embedded browser (WebView2) | MIT |
| system_tray | System tray integration | MIT |
| smtc_windows | Windows media transport controls | MIT |
| flutter_rust_bridge | FFI code generation | MIT |
| path_provider | Platform directory paths | BSD-3-Clause |
| file_picker | Native file/folder picker | MIT |
| http | HTTP client (MusicBrainz API) | BSD-3-Clause |
Website
| Package | Purpose | License |
|---|---|---|
| Astro | Static site generator | MIT |
| Inter | Typeface | OFL-1.1 |
Server Infrastructure
| Software | Purpose | License |
|---|---|---|
| Linux (Ubuntu) | Operating system | GPL-2.0 |
| nginx | Web server / reverse proxy | BSD-2-Clause |
| PostgreSQL | Account database (planned) | PostgreSQL License |
Heritage
LoonBox is a spiritual successor to Songbird (POTI Inc., 2006-2010) and Nightingale (community, 2012-2018). LoonBox is a complete rewrite — no code from Songbird or Nightingale is used in the application. The git repository preserves the historical commit lineage for reference.
Songbird was originally licensed under GPL-2.0. Nightingale continued under GPL-2.0. LoonBox is independently licensed under AGPL-3.0.
Questions
For licensing questions, contact legal@loonbox.app.