NOTICE

# PyLCSS Third-Party Notices
Document Version: 1.7 Last Updated: May 24, 2026

This document outlines the third-party libraries and components used in PyLCSS, along with their respective licenses. PyLCSS is committed to respecting the intellectual property of all contributors and provides this information in accordance with open-source licensing requirements.

## Optional Native Solver Binaries

PyLCSS can launch native solver executables as separate external processes. These binaries are not Python dependencies and are not installed by `pip install -r requirements.txt`. The helper script `scripts/install_solvers.py` can download or locate them under `external_solvers/`, but each solver remains governed by its own upstream license.

### CalculiX (`ccx`)
- **Purpose**: Linear static FEA and CalculiX-in-the-loop optimization evaluations.
- **License**: GNU General Public License v2 or later, per the official CalculiX project notice.
- **Source**: [https://www.calculix.de/](https://www.calculix.de/)
- **Packaging Note**: PyLCSS writes `.inp` decks and launches `ccx` as an external process. The Windows installer helper currently prefers `ccx_static.exe` from the CalculiX 2.23 Windows binary archive because it avoids the missing MKL runtime issue of the dynamic build.

### OpenRadioss
- **Purpose**: Explicit crash/impact solve and animation conversion via Starter, Engine, and `anim_to_vtk`.
- **License**: GNU Affero General Public License v3 or later, per the OpenRadioss `COPYRIGHT.md` distributed with the upstream binaries.
- **Source**: [https://github.com/OpenRadioss/OpenRadioss](https://github.com/OpenRadioss/OpenRadioss)
- **Packaging Note**: PyLCSS writes or stages solver decks, launches OpenRadioss as an external process, and imports converted animation frames. OpenRadioss may include additional third-party runtime components in its `extlib/` directory.

### FreeCAD
- **Purpose**: Interactive parametric CAD authoring driven by the `com.cad.freecad_part` node. PyLCSS launches `FreeCAD.exe` as a subprocess (NOT in-process embedded), and uses `FreeCADCmd.exe` headless for parameter round-trips between optimisation iterations.
- **License**: GNU Lesser General Public License v2.1 or later (LGPL-2.1+).
- **Source**: [https://github.com/FreeCAD/FreeCAD](https://github.com/FreeCAD/FreeCAD)
- **Packaging Note**: PyLCSS does NOT bundle the FreeCAD binaries. The helper script `scripts/install_solvers.py --only freecad` downloads the official Windows installer wizard from the GitHub release and runs it with admin elevation; users may also point `PYLCSS_FREECAD_EXE` at an existing install. PyLCSS additionally drops a one-line hook (`Mod/PyLCSS/Init.py`) into FreeCAD's per-version user config so every save inside FreeCAD writes a sibling `.brep` + `.fcmeta.json` PyLCSS auto-imports. The hook executes a small bundled macro (`pylcss/cad/freecad_bridge/macros/pylcss_autoexport.FCMacro`) which registers a `DocumentObserver` — the macro itself is PyLCSS-authored code under the PolyForm Shield license, but it runs inside FreeCAD's LGPL process. PyLCSS opens cleanly without FreeCAD installed; only the FreeCAD Part node feature is disabled.

## 1. LGPL Licensed Software

> ⚠️ **LGPL Compliance Note**: PyLCSS is distributed as a Python source package. All LGPL-licensed libraries are dynamically linked and can be replaced by the end user. If distributing as a compiled executable (EXE, DMG), these libraries must not be statically linked. Distributors must ensure that the end-user retains the ability to replace these shared libraries with modified versions to maintain compliance with the LGPL.

### PySide6
- **Copyright**: © 2025 The Qt Company Ltd. and other contributors.
- **License**: GNU Lesser General Public License v3 (LGPLv3)
- **Source**: [https://www.qt.io/](https://www.qt.io/)
- **Note**: PyLCSS links to PySide6 dynamically. PySide6 is the official Python module from the Qt for Python project, which provides access to the complete Qt 6.0+ framework. Users have the right to replace the version of PySide6 used by this software with their own modified version.

### netgen-mesher
- **Copyright**: © 1995-2025, Joachim Schöberl and the NGSolve team
- **License**: GNU Lesser General Public License v2.1 (LGPLv2.1)
- **Source**: [https://ngsolve.org/](https://ngsolve.org/)
- **Version**: 6.2.2506+
- **Note**: PyLCSS uses netgen-mesher for automatic 3D tetrahedral mesh generation. Users have the right to replace this library with their own version.

## 2. MIT Licensed Software

The following components are licensed under the MIT License. This permissive license requires the retention of copyright notices and license text in all copies of the software.

### NodeGraphQt
- **Copyright**: © 2017-2025 Johnny Chan (jchanvfx)
- **Repository**: [https://github.com/jchanvfx/NodeGraphQt](https://github.com/jchanvfx/NodeGraphQt)
- **Version**: 0.6.43
- **Compliance Note**: This is the MIT-licensed fork by jchanvfx. It is distinct from the dsideb fork, which is licensed under the GPL.

### pyqtgraph
- **Copyright**: © 2012-2025 University of North Carolina at Chapel Hill, Luke Campagnola, and PyQtGraph developers
- **Note**: A pure-Python graphics library for scientific applications. The authors have explicitly clarified that the MIT license of PyQtGraph applies to its code regardless of the license of the underlying Qt bindings.

### nevergrad
- **Copyright**: © Meta Platforms, Inc. and its affiliates
- **Repository**: [https://github.com/facebookresearch/nevergrad](https://github.com/facebookresearch/nevergrad)
- **Note**: Developed and maintained by Meta AI Research.

### SALib
- **Copyright**: © 2013-2025 Jon Herman, Will Usher, and contributors
- **Version**: 1.5.2 (1.0+)
- **Note**: Versions 1.0+ are MIT licensed. Earlier versions of this library were licensed under the LGPL.

### pyMOTO
- **Copyright**: Copyright (c) 2023 Arnoud Delissen
- **License**: MIT
- **Source**: [https://github.com/aatmdelissen/pyMOTO](https://github.com/aatmdelissen/pyMOTO)
- **Version**: 2.0.1
- **Note**: Modular topology-optimization framework used by the voxel topology-optimization solver path.

### meshio
- **Copyright**: © 2015-2025, Nico Schlömer and contributors
- **Note**: A library for reading and writing unstructured meshes in various formats.

### QtAwesome
- **Copyright**: © 2015 Spyder Development Team
- **License**: MIT License (Python Code)

#### QtAwesome Bundled Fonts
QtAwesome bundles several third-party icon fonts. These assets are governed by their own licenses, distinct from the Python code. Attribution is provided below:

| Font Pack | License | Copyright |
|-----------|---------|-----------|
| Font Awesome (Free) | SIL Open Font License 1.1 | © Fonticons, Inc. |
| Elusive Icons | SIL Open Font License 1.1 | © Aristeides Stathopoulos |
| Material Design Icons | Apache License 2.0 | © Google LLC |
| Remix Icons | Apache License 2.0 | © RemixIcon |
| Microsoft Codicons | Creative Commons Attribution 4.0 (CC-BY 4.0) | © Microsoft Corporation |
| Phosphor Icons | MIT License | © Phosphor Icons |

### pydantic
- **Copyright**: © 2017-2026 Samuel Colvin and contributors
- **License**: MIT
- **Source**: [https://github.com/pydantic/pydantic](https://github.com/pydantic/pydantic)

### simpleeval
- **Copyright**: © 2013-2026 Daniel Fairhead
- **License**: MIT
- **Source**: [https://github.com/danthedeckie/simpleeval](https://github.com/danthedeckie/simpleeval)
- **Note**: A simple, safe single expression evaluator for Python.

### openpyxl
- **Copyright**: © 2010 Eric Gazoni, Charlie Clark
- **License**: MIT
- **Source**: [https://gitlab.com/openpyxl/openpyxl](https://gitlab.com/openpyxl/openpyxl)

### trimesh
- **Copyright**: © 2012-present, Michael Dawson-Haggerty and contributors
- **License**: MIT
- **Source**: [https://github.com/mikedh/trimesh](https://github.com/mikedh/trimesh)
- **Note**: Used for mesh loading, SDF computation, and geometry preprocessing in geometric surrogate models.

### fast-simplification
- **Copyright**: Copyright (c) 2017-2021 The PyVista Developers
- **License**: MIT
- **Source**: [https://github.com/pyvista/fast-simplification](https://github.com/pyvista/fast-simplification)
- **Version**: 0.1.13
- **Note**: Optional quadric mesh decimation backend used to simplify recovered topology-optimization STL surfaces.

### tetgen Python wrapper
- **Copyright**: Copyright (c) 2017-2026 The PyVista Developers
- **License**: MIT
- **Source**: [https://github.com/pyvista/tetgen](https://github.com/pyvista/tetgen)
- **Version**: 0.8.4
- **Note**: Python interface used for tetrahedral remeshing. The bundled/native TetGen C++ core is not MIT; see the GPL/AGPL section below.

### rtree
- **Copyright**: © 2008-2026, Sean Gillies and contributors
- **License**: MIT
- **Source**: [https://github.com/Toblerity/rtree](https://github.com/Toblerity/rtree)
- **Note**: Python bindings for libspatialindex; libspatialindex is also MIT licensed.

### pydantic-ai-slim
- **Copyright**: © 2024-2026, Pydantic Services Inc. and contributors
- **License**: MIT
- **Source**: [https://github.com/pydantic/pydantic-ai](https://github.com/pydantic/pydantic-ai)
- **Note**: Minimal distribution of Pydantic AI used with OpenAI, Anthropic, and Google provider extras for the PyLCSS assistant system.

### py7zr
- **Copyright**: © 2019-2026, Hiroshi Miura
- **License**: LGPL-2.1-or-later, used as the Python interface only.
- **Source**: [https://github.com/miurahr/py7zr](https://github.com/miurahr/py7zr)
- **Note**: Pure-Python 7z reader used as a fallback by `scripts/install_solvers.py` when extracting third-party archives. PyLCSS imports it from the venv; users may replace the wheel freely.

### MIT License Text
```text
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.
```

## 3. Apache 2.0 Licensed Software

The following components are licensed under the Apache License Version 2.0. This license allows for use and modification and includes an explicit grant of patent rights from contributors.

### cadquery
- **Copyright**: © 2015-2025, CadQuery Contributors
- **Version**: 2.6.1 (2.0+)
- **Note**: CadQuery 2.0+ is Apache 2.0 licensed. Earlier versions (pre-2.0) were LGPL.

### packaging
- **Copyright**: © 2014-2026 Python Packaging Authority
- **License**: Apache License 2.0 / BSD 2-Clause
- **Source**: [https://github.com/pypa/packaging](https://github.com/pypa/packaging)

### Apache License 2.0 Summary
```text
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

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

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

## 4. BSD Licensed Software

The following components are licensed under the BSD 3-Clause License. This license is similar to the MIT license but prohibits the use of the copyright holder's name to endorse derivative works.

### numpy
- **Copyright**: © 2005-2025, NumPy Developers

### scipy
- **Copyright**: © 2001-2002 Enthought, Inc.
- **Copyright**: © 2003-2025, SciPy Developers
- **Note**: Originally developed at Enthought, Inc., now maintained by the SciPy community.

### pandas
- **Copyright**: © 2008-2011, AQR Capital Management, LLC, Lambda Foundry, Inc.
- **Copyright**: © 2011-2025, Open source contributors and PyData Development Team
- **Note**: Originally developed at AQR Capital Management.

### networkx
- **Copyright**: © 2004-2025, NetworkX Developers

### h5py
- **Copyright**: © 2008-2025, Andrew Collette and contributors

#### h5py Bundled Components
h5py serves as a Pythonic interface to the HDF5 library. The distribution includes the HDF5 binary library.

| Component | License | Copyright |
|-----------|---------|-----------|
| HDF5 | BSD-style (The HDF Group License) | © The HDF Group |

### pint
- **Copyright**: © 2012-2025 Hernan E. Grecco and contributors

### scikit-learn
- **Copyright**: © 2007-2025, scikit-learn developers

### torch (PyTorch)
- **Copyright**: © 2016-present, Meta Platforms, Inc. (formerly Facebook, Inc.)
- **Note**: Developed and maintained by Meta AI Research.

### joblib
- **Copyright**: © 2008-2025, The joblib developers

### dill
- **Copyright**: © 2004-2025, The Uncertainty Quantification Foundation, California Institute of Technology, and contributors

### vtk (Visualization Toolkit)
- **Copyright**: © 1993-2025, Ken Martin, Will Schroeder, Bill Lorensen
- **Copyright**: © 2000-2025, Kitware, Inc.
- **Note**: Developed and maintained by Kitware, Inc.

### scikit-fem
- **Copyright**: © 2018-2025, scikit-fem developers

### scikit-image
- **Copyright**: © 2009-2025, scikit-image team

### PyAutoGUI
- **Copyright**: © 2011-2026 Al Sweigart
- **License**: BSD 3-Clause
- **Source**: [https://github.com/asweigart/pyautogui](https://github.com/asweigart/pyautogui)

### numba
- **Copyright**: © 2012-2026, Anaconda, Inc. and contributors
- **License**: BSD 2-Clause
- **Source**: [https://github.com/numba/numba](https://github.com/numba/numba)
- **Note**: High-performance JIT compiler for Python numerical code.

### pyperclip
- **Copyright**: © 2014-2026 Al Sweigart
- **License**: BSD 3-Clause
- **Source**: [https://github.com/asweigart/pyperclip](https://github.com/asweigart/pyperclip)

### numpy-stl
- **Copyright**: © 2013-2026 WoLpH (Rick van Hattem)
- **License**: BSD 3-Clause
- **Source**: [https://github.com/WoLpH/numpy-stl](https://github.com/WoLpH/numpy-stl)

### pypardiso
- **Copyright**: Copyright (c) 2016, Adrian Haas and ETH Zurich
- **License**: BSD 3-Clause
- **Source**: [https://github.com/haasad/PyPardiso](https://github.com/haasad/PyPardiso)
- **Version**: 0.4.7
- **Note**: Python interface to Intel MKL Pardiso for sparse linear solves.

### crackle-codec
- **Copyright**: Copyright (c) 2022,2023 William Silversmith
- **License**: BSD 3-Clause
- **Source**: [https://github.com/seung-lab/crackle](https://github.com/seung-lab/crackle)
- **Version**: 0.42.0
- **Note**: Dense 3D segmentation compression codec used by the kimimaro skeletonization dependency stack.

### BSD 3-Clause License Text
```text
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

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

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.

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, 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.
```

## 5. GPL/AGPL Licensed Software

The following components are copyleft-licensed. If these packages are bundled or distributed with PyLCSS, distributors must satisfy the applicable GPL or AGPL obligations.

### kimimaro
- **Copyright**: Jingpeng Wu, William Silversmith, and contributors
- **License**: GPL-3.0-or-later
- **Source**: [https://github.com/seung-lab/kimimaro](https://github.com/seung-lab/kimimaro)
- **Version**: 5.8.1
- **Note**: TEASAR-style skeletonization dependency for dense labeled 3D volumes.

### TetGen C++ core (via tetgen)
- **Copyright**: TetGen authors and contributors
- **License**: AGPL-3.0-or-later or commercial license from WIAS
- **Source**: [https://github.com/libigl/tetgen](https://github.com/libigl/tetgen)
- **Version**: 1.6.0 source bundled by tetgen 0.8.4
- **Note**: The PyVista `tetgen` Python wrapper is MIT licensed, but the underlying C++ TetGen source is distributed under a dual AGPL/commercial licensing scheme.

Full GPL-3.0 text is available at: [https://www.gnu.org/licenses/gpl-3.0.html](https://www.gnu.org/licenses/gpl-3.0.html)
Full AGPL-3.0 text is available at: [https://www.gnu.org/licenses/agpl-3.0.html](https://www.gnu.org/licenses/agpl-3.0.html)

## 6. Additional License Texts

### SIL Open Font License 1.1
The following fonts are licensed under the SIL OFL 1.1:
- Font Awesome (Free)
- Elusive Icons

**PREAMBLE**
```text
The goals of the Open Font License (OFL) are to stimulate worldwide development of collaborative font projects, to support the font creation efforts of academic and linguistic communities, and to provide a free and open framework in which fonts may be shared and improved in partnership with others.

The OFL allows the licensed fonts to be used, studied, modified and redistributed freely as long as they are not sold by themselves.
```
Full text available at: [https://scripts.sil.org/OFL](https://scripts.sil.org/OFL)

### Creative Commons Attribution 4.0 (CC-BY 4.0)
The Microsoft Codicons bundled with QtAwesome are licensed under CC-BY 4.0. Full text available at: [https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/)

## 7. Version Verification

The following versions are explicitly verified for license compliance. Deviating from these versions or sources may alter the licensing obligations.

| Library | Version | License | Notes |
|---------|---------|---------|-------|
| NodeGraphQt | 0.6.43 | MIT | Must be the jchanvfx fork. Do not use the GPL-licensed dsideb fork. |
| CadQuery | 2.6.1 | Apache 2.0 | Version 2.0+ required (pre-2.0 versions were LGPL). |
| SALib | 1.5.2 | MIT | Version 1.0+ required (pre-1.0 versions were LGPL). |
| fast-simplification | 0.1.13 | MIT | Optional quadric decimation backend for recovered TopOpt STL surfaces. |
| pyMOTO | 2.0.1 | MIT | Topology-optimization framework used by the voxel TopOpt solver. |
| tetgen | 0.8.4 | MIT wrapper / AGPL core | Python wrapper is MIT; bundled TetGen C++ source is AGPL-3.0-or-later or commercial. |
| pypardiso | 0.4.7 | BSD 3-Clause | Sparse linear solver interface for MKL Pardiso. |
| kimimaro | 5.8.1 | GPL-3.0-or-later | Skeletonization dependency; review distribution obligations before bundling. |
| crackle-codec | 0.42.0 | BSD 3-Clause | Runtime dependency in the kimimaro stack. |

---

For more information about PyLCSS and its licensing, please refer to the LICENSE file or visit the project repository.