Free and open source software

Free software is software whose licence grants every user the freedom to run it, study its source code, modify it and redistribute it. The expression open source describes the same reality from a more technical angle. Free software is not software without rights: it remains protected by copyright, and the freedoms granted come from a licence whose conditions bind the user.

The families of free software licences

First, so-called permissive licences, such as the MIT, BSD or Apache licences, which allow reuse of the code, including in proprietary software, subject mainly to keeping the copyright notices. Next, strong copyleft licences, such as the GNU General Public License, which require any distributed derivative work to be placed under the same licence, with disclosure of the source code. Finally, weak copyleft licences, such as the LGPL or the European Union Public Licence, which limit this obligation to the modified component. The choice of licence determines what the company may do with the code and what it owes in return.

The risks for the company

Integrating a free component into a commercial product may, depending on the licence, require the company to publish its own source code. This contamination risk must be analysed before integration, through an inventory of the components and their licences. Breach of a free licence is sanctioned. The Cour de cassation held in 2022, in a dispute between the publisher of free software and a telecommunications operator, that non-compliance with the conditions of such a licence falls within Infrigement and not merely contractual liability. The applicable texts can be consulted on Légifrance.

Key points

In practice, managing free software requires an internal policy: inventory of components, checking the compatibility of licences with one another, compliance with notice and source code disclosure obligations, suitable clauses in the development agreements and software licences concluded with customers. The firm advises on these issues and acts in compliance disputes, as presented on the page contracts.