AxoSyslog License Update: Moving to GPL3

As part of the 4.12 release, we are updating the license for AxoSyslog, our fork of syslog-ng™, to a single, clear open source license: GNU General Public License version 3 or later (GPL-3.0-or-later). We believe this change simplifies AxoSyslog's legal foundations, supports a more vibrant contribution model, and aligns better with modern open source usage patterns.

GPL3 is the most generic version of the GPL, preferred by the Free Software Foundation over LGPL or AGPL or any other license provided by them.

What’s Changing?

Previously, AxoSyslog used the licenses inherited from syslog-ng, which was a combination of:

LGPL-2.1-or-later for most of the core code, and
GPL-2.0-or-later for some modules and utilities.

While both are well-established free software licenses, the dual-license model meant complexity for contributors and downstream users. Adopting a single license (GPL-3.0-or-later) across the entire AxoSyslog codebase simplifies this situation.

Why This Change?

We chose GPL-3.0-or-later for several reasons:

Clarity: A single license makes it easier for developers, contributors, and legal teams to understand their rights and responsibilities.
Modern legal protections: GPLv3 includes stronger protections around tivoization, digital rights management, and software patents.
Compatibility: Many modern open source components (such as systemd and other infrastructure tooling) are licensed under GPLv3 or compatible terms.
Future-proofing: The “or later” clause ensures that AxoSyslog can evolve in step with future GPL versions without another license change.

What Does This Mean for You?

If you use AxoSyslog: You may continue to use and distribute it under GPL-3.0-or-later. This license ensures the same freedom to use, study, modify, and share the software—now with stronger community protections.
If you contribute to AxoSyslog: All contributions going forward must be GPL-3.0-or-later compatible.
If you embed or redistribute AxoSyslog in full or in portions: The GPL-3.0-or-later license requires that you provide source code and retain license notices, among other standard requirements.
If your project is using AxoSyslog images: Projects that redistribute binaries/images will need to include instructions where to get the source code (link to its original location). Alternatively, they can include the source code or a written offer.

We recommend reviewing the GPL-3.0-or-later license text if you have questions about redistribution or integration, we are also happy to answer any questions you may have.

What About syslog-ng?

We respect the long-standing contribution of the syslog-ng project and its maintainers. AxoSyslog began as a fork but has since diverged in architecture, performance, features, and now licensing. This license change further reflects our independent direction and commitment to clear, community-focused open source governance and AxoSyslog's intention of becoming the upstream for the project.

Looking Ahead

We’re looking forward to continuing the steady development of AxoSyslog, now under a new license. As always, we welcome your feedback and contributions. If you have questions or comments, feel free to open an issue or reach out directly.

Thanks for being part of the AxoSyslog community.

— The AxoSyslog Team

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