License and credits
BUI is free software under GPL-2.0-or-later, because it's built from Blender. What that means, the licenses of the parts BUI includes, and the projects it stands on.
BUI is free software. You can use it, study it, change it and share it. It exists because thousands of people built Blender’s interface over decades and shared it under a free license; BUI keeps that promise going.
BUI’s license: GPL-2.0-or-later
BUI is derived from Blender’s source code, which is licensed under the GNU General Public License, version 2 or later, so BUI is too. Every source file keeps its SPDX header:
SPDX-License-Identifier: GPL-2.0-or-laterThe Python package (pyproject.toml), the Rust crates (Cargo.toml) and the npm packages (package.json) all declare GPL-2.0-or-later. The repository’s LICENSE file holds the text of version 3 of the GNU GPL, one of the versions that “or later” covers.
What it means for you
In plain words, and not as legal advice:
- Using BUI to build and run your own programs is free, for any purpose, commercial included.
- Changing BUI is free too.
- Distributing a program that includes BUI (shipping an app, publishing a package) means distributing it under the GPL as well, with its source code available to the people you give it to.
If you need different terms, ask a lawyer before you ship.
Contributing
Contributions are accepted under the same license, and new files carry the same SPDX header. See Contributing.
Third-party parts
Some parts of BUI come from other projects and keep their own licenses:
| Part | What it does in BUI | License |
|---|---|---|
| Blender sources | Widget drawing, interaction rules, theme, icons, blenlib, GHOST window code, the file browser and node editor |
GPL-2.0-or-later |
| Dear ImGui by Omar Cornut | The immediate-mode GUI that runs on BUI | MIT |
| Inter by Rasmus Andersson | The embedded UI font, as in Blender (gpu/extern/Inter-LICENSE.txt) |
SIL Open Font License 1.1 |
| FreeType 2.13.3 | Glyph loading, hinting and rendering, like Blender’s BLF | FreeType License or GPLv2 (dual-licensed) |
| stb_truetype by Sean Barrett | Font metrics, and the fallback text rasterizer | Public domain |
| NanoSVG by Mikko Mononen, as edited by Blender | Rasterizing Blender’s SVG icons | Zlib |
| Slug by Eric Lengyel | The GPU glyph coverage algorithm (shader code “Copyright 2017 by Eric Lengyel”) | MIT |
| Tailwind CSS | The v4 default theme values behind the Tailwind support | MIT |
The Rust and JavaScript bindings also depend on crates and packages such as taffy, napi-rs, React and QuickJS, each under its own license.
Acknowledgments
BUI stands on the work of many people. Thank you to:
- Blender and its community: the UI this project is built from, including its GHOST window code and
blenlib. - Dear ImGui by Omar Cornut: the immediate-mode GUI that runs on BUI.
- taffy: flexbox, grid and block layout for the Rust crate.
- Tailwind CSS: the v4 theme behind the Tailwind support.
- stb_truetype: the text engine.
- Inter by Rasmus Andersson: the embedded UI font, as in Blender.
- Slug by Eric Lengyel: the GPU glyph coverage algorithm.
- gpui, zopra and Leptos: the APIs the Rust syntax follows.
Next steps
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