The CGAL License

Since release 3.0, CGAL is available under an Open Source license as well as a commercial license. Users choosing to use CGAL under the free-of-charge Open Source license have to comply to its terms, otherwise they have to buy a commercial license.

We informally describe below our license scheme, that is, which rights we give to users. Also, do not hesitate to contact us for any question regarding the license.

The Open Source License

Some parts of CGAL are available under the LGPL, other parts are under the QPL. These two licenses introduce different constraints.

The idea is that the fundamental building blocks of CGAL are under the LGPL because this is a less constraining license which allows more people to build on top of this code without much constraints. This helps making the CGAL design a de-facto standard for geometric code which helps interoperability. The higher-level algorithms are typically released under the QPL in order to protect their commercial value. This makes it possible for us to exploit it commercially, which guarantees long term support, maintenance and further developments of the code for the benefit of the project and its users.

The Package Overview web page gives the license of each package. Approximately, the Kernel and Support libraries are under the LGPL, and most geometric algorithms and data structures are under the QPL, but there are some exceptions in both directions.

For the exact and formal details of the license, please always refer to the LICENSE file from the CGAL source code distribution.

The LGPL

The Lesser General Public License (v2.1) gives you the right to use and copy the code freely. It is also possible to modify the code under the condition that the resulting modification is released as source code under the LGPL with any binary distribution that you may do of a resulting application using these LGPL parts.

The QPL

The Q Public License gives you the right to use the code under the condition that any program using it be released itself under a QPL-compatible Open Source license. This also applies to programs that are not distributed (used only internally). We also consider that these usage restrictions apply to code using CGAL via a redirection layer built on top of CGAL (redefining the interface - e.g. in a different programming language -, or communicating via files, pipes, sockets, RPC, or other IPC mechanisms...). Concerning modifications, they are allowed under the condition that they be distributed as patches against the original sources.

GPL-QPL Incompatibility Note

The General Public License (GPL) has a viral effect which makes it incompatible with the QPL. For more information, please refer to the paragraph about the QPL on the licenses web page of the FSF. It is therefore not possible to build a program including GPL code and some QPL parts of CGAL. In this case, if you are the copyright owner of the GPL code, you can amend the license by adding an exception allowing the use of CGAL with it (see again the FSF web page).

The Commercial License

In cases where the constraints of the Open Source license prevent you from using CGAL, you can buy a commercial license for CGAL or parts of CGAL from GeometryFactory. The commercial offer is adapted to academic/research and industry customers.