The OpenFOAM® Foundation is a non-stock, nonprofit corporation, founded in August 2011 whose “specific objectives and purposes... shall be to ensure and facilitate the free open source distribution of the OpenFOAM software to the general public” (Cert. of Incorporation, Article III).
The Foundation has taken on the guardianship of the OpenFOAM software, previously undertaken by OpenCFD Ltd since 2004. It holds the copyright to the entire source code of OpenFOAM, through the initial transfer of copyright from OpenCFD in 2011, and by subsequent copyright transfers of more recent code.
As the copyright holder, the Foundation licenses OpenFOAM free and open source only, under the GNU general public licence (GPL). The GPL gives users the freedom to modify and redistribute the software and a guarantee of continued free use — as long as the terms of the GPL are adhered to.
In particular, there are terms to the GPL that provide protection against exploitation by companies including OpenFOAM within non-free and/or closed source software products. First, when any modified version of the software is redistributed, the source code must also be made available by the distributor. Secondly, any modified version can only legally be distributed open source under the GPL, without limiting the rights on further redistribution. Software that links intimately enough to OpenFOAM has to be distributed under the GPL as well. Copyright statements on the software must remain intact.
The OpenFOAM Foundation exists to ensure that OpenFOAM will always be available to the general public free and open source only. In return, we expect members of the public to adhere to the terms of the GPL and urge others to do the same.