About ARTooKit's Licensing

What license does the ARToolKit project use?

ARToolKit versions 5.2 and later are made available freely under the GNU Library General Public License version 3 (LGPLv3), with the addition of a special exception permitting static linking.

Other files included with ARToolKit may be licensed under other terms or made available for use without requiring a license. Where applicable, such terms are noted in the file to which they apply.

libKPM is licensed under special terms. The text of that license is can be found in the header and source files to which it applies.

Complete licensing information can be viewed here: https://github.com/artoolkit/artoolkit5/blob/master/LICENSE.txt

Why LGPLv3?

We believe this license offers the right mix between options for commercial use and community development. Developers are freely availed of the ARToolKit source code, and the ARToolKit open source project benefits in return from enhancements, bug reports, and external development ideas.

Please read the full text.

Version 3 of the LGPL license includes a number of useful clarifications of users' rights, including providing access to source, and means of distribution. You can read about these changes from v2.1 of the license here: http://www.gnu.org/licenses/quick-guide-gplv3.html

What are some things I need to do to be in compliance with ARToolKit's license?

Full compliance requires reading the license and following its directives, but some things that you must do include:

  • If your program is interactive, you need to display to users the fact that your program includes ARToolKit under the LGPLv3 license, and provide either the full text of the GPLv3 and LGPLv3 license or a link to these. An "About" dialog is a good place to place this acknowledgement and notice. For iOS apps, a Settings pane is also a good place to show this notice.
  • If you modify the source of ARToolKit and then use this modified source in your program, you need to make available the source of your modifications of ARToolKit. The best way to do this is to fork the ARToolKit public repository on GitHub and publish your modifications in your fork.

Can I use ARToolKit's LGPLv3 libraries in a GPL-licensed program?

Yes, but only in a GPLv3 program. GPLv2 is not compatible with LGPLv3. See the diagram under the header "New Compatible Licenses" on this page: http://www.gnu.org/licenses/quick-guide-gplv3.html#new-compatible-licenses

What about libKPM?

libKPM, which performs key-point matching for NFT page recognition and initialization now use a FREAK detector framework, contributed by DAQRI. Unlike the previous commercial version of libKPM which used SURF features, FREAK is not encumbered by patents. libKPM now joins the other core ARToolKit libraries under an LGPLv3 license. Additionally the new libKPM no longer has dependencies on OpenCV's FLANN library, which should simply app builds and distribution on all supported platforms.

Existing holders of a commercial license to ARToolKit Professional v5.x may use libKPM from ARToolKit v5.2 under the terms of their current license for the remainder of its duration. Please contact us if you are an existing user of ARToolKit Professional with questions.

What should I do if I spot a license violation?

If you are aware of use of ARToolKit v5.2 and later outside the LGPLv3 license terms (e.g. use of a modified version without publication of those modifications, or any other license violation), please contact the ARToolKit project administrators. We are proactive in encouraging users to follow the license terms.

How can I contribute back to the project?

If you wish to publish modifications to the ARToolKit, but are unsure of the technical process involved in contributing via distributed version control, you can also provide code via other means. Please contact the project administrators.

What about older versions of ARToolKit?

ARToolKit versions 1.0 through 2.x were made available under the GNU General Public License version 2 (GPLv2). Please read the full GPLv2 text here.

Commercial licenses to ARToolKit Professional versions 2.0 through 5.1.7, previously available from ARToolworks, Inc., are no longer available.