A free software is a program whose source code is accessible, modifiable, and redistributable by anyone, according to the terms of a specific license. This definition is based on four freedoms articulated by Richard Stallman in the 1980s: to run the program, to study how it works, to redistribute copies, and to distribute modified versions. These freedoms do not concern the price, but the control that each user retains over the tool.
Copyleft and permissive licenses: what the law changes concretely
The license determines what a user or a company can do with the source code. Two main families coexist, and the choice of one or the other profoundly changes how a project evolves.
Copyleft licenses (GNU GPL, AGPL) require that any derivative version of the software remains published under the same license. A publisher who integrates GPL code into their product must make their own code accessible. This mechanism prevents the privatization of a community project.
Permissive licenses (MIT, BSD, Apache 2.0) allow the reuse of code in proprietary projects without any obligation of reciprocity. Entire segments of commercial infrastructures rely on code published under the MIT license, without the companies exploiting it contributing in return.
This distinction has direct consequences on the sustainability of projects. Software under copyleft mechanically generates an ecosystem of open contributions, whereas a project under a permissive license may see its improvements captured by a private actor. To better understand the community dynamics around these licenses, a useful resource: https://www.mondelibre.org/, which documents the news and debates of the Francophone free software movement.
Digital sovereignty: European migrations to free software
The topic of free software has moved from the activist sphere to the budgetary and strategic decisions of public administrations. Several European states have initiated massive migrations since 2024, with specific timelines.
The German state of Schleswig-Holstein aims for a complete exit from the Microsoft ecosystem. About 80% of the 30,000 administrative positions were already running on LibreOffice by 2025, email has transitioned to Open-Xchange and Thunderbird, and a migration to Linux desktop is planned by 2030.
Denmark announced in the summer of 2025 the migration of its agents to Linux and LibreOffice. A few months after the announcement, about half of the affected positions had already transitioned.
These decisions are not based on ideological choices. They respond to a recognition of critical dependence on foreign publishers, with recurring licensing costs and a loss of control over public data. Switzerland is preparing an open-source plan B in response to Microsoft 365, indicating that the trend surpasses the isolated cases often cited in the past.
Cyber Resilience Act and security of open source code
The European regulation Cyber Resilience Act (CRA), adopted in 2024, gradually imposes reporting obligations on publishers of digital products regarding actively exploited vulnerabilities. This regulation also applies to free software when distributed in a commercial context.
The transparency of the source code provides a structural advantage here. Software whose code is readable by all allows:
- An independent audit by any developer or security organization, without relying on the goodwill of a publisher
- A quick fix of vulnerabilities thanks to the community of contributors, whereas a proprietary publisher may delay a patch for commercial reasons
- A complete traceability of modifications made to the program, with each change documented in the public history of the project
The CRA creates tension for freely maintained projects. A solo developer who publishes a free tool used by thousands of companies faces compliance obligations designed for structured publishers. The GNU community and several foundations have raised concerns about this, calling for clear exemptions for non-commercial contributors.
Free software in daily life: beyond the operating system
The impact of free software goes beyond the workstation. Firefox, VLC, LibreOffice, Thunderbird are consumer tools whose source code is open. The Apache web server and the Linux kernel power the majority of servers that host the websites visited every day.
For small businesses, free software offers a concrete lever:
- The elimination of recurring licensing costs, replaced by a one-time investment in training or integration
- The ability to have the software audited or adapted by any service provider, which eliminates dependence on a single vendor
- Access to open formats (ODF, PDF/A) that ensure the long-term readability of documents, without planned obsolescence by a publisher
The downside exists. Free software without an active community can become a risk: no security updates, incomplete documentation, incompatibilities with third-party tools. Evaluating the vitality of a project (commit frequency, number of contributors, responsiveness to tickets) is part of the decision, just like choosing a proprietary publisher.
The free software movement now structures public policies, cybersecurity standards, and infrastructure choices on a continental scale. The question is no longer whether free software is viable, but how organizations manage the transition to tools over which they have control of the code, data, and costs.
