The history of free software dates back to the early days of computing (more information here in french).
It is a long-standing tradition in academic research.

The term ‘free software’ should not be confused with ‘royalty-free’ works.

The term ‘Free Software’ refers to the freedom for users to run, copy, distribute, study, modify and improve the software. More specifically, it refers to four types of freedom for the software user:

The freedom to run the programme for any purpose.
The freedom to study how the programme works and adapt it to your needs. Access to the source code is a prerequisite.
The freedom to redistribute copies.
The freedom to improve the programme and publish your improvements for the benefit of the whole community. Access to the source code is a prerequisite.

Free software does not mean ‘non-commercial’.

Open Source vs free software

Both aim to give users more freedom. It’s not easy to tell the difference.

According to Richard Stallman, the fundamental difference between the two concepts lies in their philosophy:

‘Open source is a development methodology; free software is a social movement’.

FLOSS stands for Free/Libre/Open-Source Software, a term that encompasses both free and open-source software.

For more information about these 2 concepts.

Types of free licenses

There are different types of free licenses:

without copyleft: the initial license does not apply. Permission to redistribute and modify, but also to add restrictions.
weak copyleft: the initial license remains in force, although additions may be subject to a different license.
strong copyleft: the initial license applies to everything. A contaminating licence.

Type	Examples of license
Without copyleft	BSD license Apache License 2 MIT CeCILL-B
Weak copyleft	GNU library or « Lesser » General Public License (LGPL) CeCILL-C
Strong copyleft	GNU General Public License EUPL CeCILL

In order to avoid a proliferation of licences, the Law for a Digital Republic has provided for the creation of a list, set by decree, of licences that can be used by administrations to re-use their public information free of charge, whether it is data or software source code (article D.323-2-1 of the Code of relations between the public and the administration):

Consult this list (in french).

Example of the GPL license:

This is the best-known and most widespread licence in the world of free software. It authorises the following without the author’s consent or the risk of legal action:

use of the software,
studying how the software works,
adapting the software to the user’s needs,
copying and distribution to friends or colleagues,
improvement of the software by the user and distribution of the modified software to the public.

WARNING: this is a contaminating licence! It requires the user to redistribute these modifications under the GPL licence => Thus, all software reusing a piece of GPL code is contaminated by the GPL.

Example of the BSD license:

BSD = Berkeley System Distribution license

This license is not very restrictive: software distributed under the BSD license may be freely copied or modified. The only constraint is that all derivative works, documentation, and advertising relating to these works must include a visible reference to the license itself and mention the authors of the original software.

Note: in the case of very popular software, the number of authors is often very large. Listing all contributors is therefore complex and difficult to read. To eliminate this inconvenience, version 2 of the BSD license removes the obligation to list authors.

Version 2 of the BSD license is therefore one of the least restrictive available.

Note that the numerique.gouv.fr web site recommends two default licenses: