License

Turian Engine is free and open-source software licensed under the Mozilla Public License version 2.0 (MPL 2.0). A copy of the license is included in every distribution or can be read at https://mozilla.org/MPL/2.0/.

Why MPL 2.0

We chose MPL 2.0 to give every developer — solo creators, indie teams, mid-size studios, and large companies — the freedom to build commercial games without restrictions. At the same time, we want improvements to the engine itself to be shared back with the community.

MPL 2.0 achieves this with file-level copyleft: if you modify the engine and distribute it, you share those changes. But your game — the code, art, and data you create — is entirely yours under any license you choose. This means studios of any size can contribute to Turian, benefit from everyone else's contributions, and ship exactly the games they want to ship.

What this means for your games

Creating a game with Turian does not require you to release its source code, license it under the MPL, pay any royalty, or become a member. The engine is a tool you use to build your game. The game's own code and assets are your work and your copyright — yours to sell, open-source, or keep private, under any license you choose.

You can build and distribute proprietary games with Turian. The MPL 2.0 covers only the engine source files; your game code, scripts, artwork, sounds, and data are entirely yours.

What this means if you modify the engine

If you distribute a modified version of the engine (for example, a fork of the repository or a custom build with your own changes), the MPL 2.0 requires:

• Source for changes — you must provide the source code for files you modified in the engine.
• Same license for engine files — modified engine files must be distributed under the MPL 2.0 (or a compatible license).
• Prominent notice — you must state which files you modified and include a summary of changes.

The MPL 2.0 covers only the engine source files. Your game code, scripts, artwork, sounds, and data are entirely yours and can be licensed however you choose.

This only applies when you distribute the modified engine to others. If you modify the engine internally — for your own game, within your team or studio — the MPL 2.0 does not require you to release those changes. You can keep your internal fork private and use it to build and ship your games. Only when you hand the modified engine itself to someone outside your organisation do the copyleft obligations apply.

Contributions

When you share code, documentation, or assets with Turian, you're giving them to the community for free. It's that simple — no separate paperwork, no fees, no ownership disputes. Just submit your work and contribute to something that helps everyone.

Your contributions help the entire community, including yourself. We keep things simple: just code, shared openly.

Contribution license

By submitting any contribution (including code, documentation, or assets) to this repository, you agree to the following terms:

You license your contribution under the project's primary outbound license (Mozilla Public License 2.0).

You grant the project maintainer(s) a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to distribute, adapt, dual-license, or relicense your contributions under any alternative terms at their sole discretion.

Third-party code

The Turian repository includes third-party code under various permissive licenses:

Each component retains its original copyright. The combination as a whole is licensed under the MPL 2.0, but the individual permissive components may also be used separately under their own terms.

Brand and trademarks

The "Turian" name, logos, and related branding assets are not covered by the MPL 2.0 and remain the sole copyright of Bruno Massa. They may not be used to imply endorsement or association with derivative products without explicit permission.

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