MIT License

Copyright (c) 2026 Tobias Karusseit

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

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Third-party notices
================================================================================

cthreads depends on (or may optionally link / redistribute) the following
third-party components. Their licenses apply to those components only.
Full license texts are available from the upstream projects.

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pybind11
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Used to bind the native `_ext` module to Python (FetchContent or system
package via CMake).

License: BSD-3-Clause
Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>, All rights reserved.
Homepage: https://github.com/pybind/pybind11

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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Vulkan (Khronos Group) — optional, CTHREADS_GPU=ON
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GPU builds use Vulkan headers from the Vulkan SDK / CMake Vulkan package.
At runtime, cthreads loads the system Vulkan loader (for example vulkan-1)
dynamically; the loader and ICD are provided by the platform / GPU vendor
and are not redistributed as part of cthreads by default.

Vulkan-Headers / related Khronos materials are typically licensed under the
Apache License, Version 2.0.
Homepage: https://github.com/KhronosGroup/Vulkan-Headers
License reference: https://www.apache.org/licenses/LICENSE-2.0

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Khronos glslang — GPU GLSL -> SPIR-V (CTHREADS_GPU=ON)
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When built with CTHREADS_GPU=ON, cthreads FetchContent-vendors and statically
links Khronos glslang into `_ext` to implement `_ext.gpu.compile_glsl`.
This is the same compiler engine Google shaderc wraps. End users of a GPU
wheel do not need glslc or the Vulkan SDK shader tools.

License: Apache License, Version 2.0 (with BSD-style components in the tree)
Homepage: https://github.com/KhronosGroup/glslang
License reference: https://www.apache.org/licenses/LICENSE-2.0

Upstream license text is copied at build time into:

    cthreads/gpu/third_party_notices/

(see README.md there). Redistribute that directory with any binary that
includes the GPU extension.

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scikit-build-core
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Used as the Python build backend to drive CMake (build-time dependency; not
part of the runtime import of cthreads).

License: Apache License, Version 2.0
Homepage: https://github.com/scikit-build/scikit-build-core
License reference: https://www.apache.org/licenses/LICENSE-2.0

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Apache License, Version 2.0 (summary for Apache-licensed deps above)
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You may reproduce and distribute copies of Apache-2.0 works under the terms
of that license. A copy of the full license text is available at:

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the Apache License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the Apache License for the specific language governing permissions and
limitations under the License.

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Python
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cthreads is designed to run on CPython. The Python interpreter and standard
library are governed by the Python Software Foundation License.
Homepage: https://www.python.org/
