TetGen Licensing FAQ

1) Q.: What are the licensing conditions for TetGen ?

TetGen is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License (AGPLv3), or (at your option) any later version. A copy of the AGPLv3 is reproduced here. TetGen is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

2) Q.: Sorry, but under these conditions I will be unable to use TetGen. My company is selling the software it produces and makes a living from that. If we take the AGPL seriously, we would starve, or we cannot use TetGen.

If the terms and conditions of the AGPL v.3. would prevent you from using TetGen, please consider the option to obtain a commercial license for a fee. These licenses are offered by the Weierstrass Institute for Applied Analysis and Stochastics (WIAS). As a rule, licenses are provided "as-is", unlimited in time for a one time fee. Please send corresponding requests to tetgen@wias-berlin.de. Please do not forget to include some description of your company and the realm of its activities.

3).Q.: How much is a commercial license then ?

Price quotes are provided upon request. Please do not hesitate to contact tetgen@wias-berlin.de for a quote.

4) Q.: Which support do you give ? How can we be sure that bugs are fixed immediately ?

WIAS as a research institute has no infrastructure to provide 24/7 support, therefore both open source and commercial licenses do not cover support. That said, nevertheless effort is made to keep the reputation of TetGen high and to fix bugs within reasonable time.

For customers buying a commercial license, special arrangements can be made which include testing of TetGen on a specfied limited number of inputs.

Please be aware of the fact that mesh generation is an active research field, and that some shortcomings of TetGen may be due to the fact that for you particular case, the right algorithm has not yet been found.

On the other hand, please consider that due to the Open Source licensing policy there is a huge number of TetGen use cases and that the feedback from these users already helped to make it more stable.

5) Q.: How much, if any, informal support can one realistically expect beyond bug fixes? Is it possible to make reasonable requests for feature enhancements?

TetGen is the result of a research project in mesh generation for numerical calculations. As such it has its own agenda for future improvements. The main field of interest are anisotropic meshes which are able to resolve interior and boundary layers in an optimal way. This is however a hard topic, and it is not possible to give any estimate concerning a first release with such features.

Correspondingly, the resources to implement "features on demand" are limited. If a feature requested by a number of users can be implemented within reasonable time, there is a chance that such suggestions are followed.

There is also the option of a paid development contract which would allow to re-finance at least a part of the specific development costs.

6) Is your commitment to maintaining and developing TetGen limited to a known time horizon ?

Not for the forseeable future. As long as the mesh generation group at WIAS has sufficient scientific output and regular financial input from research contracts, licensing and research funding, the project will have a good chance to be continued.

(We thank Ch. Barghiel from sidefx for asking questions 5 and 6).