3rd February 2017

Enforcing the GPL

OpenFOAM is one of the leading software applications for computational fluid dynamics . It is licensed free and open source only under the GNU General Public Licence version 3 (the “GPL”)  by the OpenFOAM Foundation, the copyright holder of the software. One reason for OpenFOAM’s popularity is that its users are granted the freedom to modify and redistribute the software and have a right of continued free use, within the terms of the GPL.

OpenFOAM is developed and maintained by individuals who willingly contribute their work free and open source, with the support and consent of the organisations that employ them. Under the OpenFOAM Contributor Agreement, they transfer ownership of their contributions (or grant sufficient rights) to the OpenFOAM Foundation to enable it to enforce the GPL most effectively under single ownership.

The OpenFOAM Foundation is thereby solely responsible for enforcing the licence of OpenFOAM, to protect the rights of contributors who make a conscious decision to release their work free and open source. Users should welcome and encourage licence enforcement, because without it, the contributors — who are the lifeblood of OpenFOAM — would inevitably withdraw their support.

The Foundation will act swiftly on any report it receives of a potential licence infringement. For example, in November 2016, we received a report concerning CFD Support S.R.O, from the Czech Republic, who were distributing OpenFOAM in modified form. Our audit of the software they distributed found that the original copyright and licence notices had been removed, in breach of clause 4 of the GPL.  Some original source code was also deleted and several additional executable applications and shared-object libraries were included, without conveying the source code, in breach of clause 6. Notably, one new library was to lock the installation, requiring the user to obtain a key to use the software. There were no notices stating the software was modified, in breach of clause 5.

CFD Support were issued a notice of breach and termination of the GPL by lawyers representing the Foundation. They were given 30 days to remedy all breaches of the GPL, in accordance with clause 8 of GPL. CFD Support remedied all breaches and the Foundation agreed to accept a payment from CFD Support in respect of legal costs and damages. The Foundation is pleased to have resolved this matter.

Again, it is good news for users that the Foundation takes action like this to retain the support of the contributors to OpenFOAM. But investigating a potential breach of the GPL involves time and effort from those contributors, which would be more usefully spent on improving OpenFOAM for the benefit of all.

It is ultimately to the benefit of all users to learn the basics of the GPL, understand the implications of the GPL and avoid modified versions of OpenFOAM that breach the GPL terms.