GPL (GNU General Public License)

The GNU General Public License (GPL) is the most widely used strong copyleft software license, authored by the Free Software Foundation. It guarantees that everyone who receives a covered program also receives the freedom to run, study, share, and modify it. Critically, any derivative work that is distributed must itself be licensed under the GPL and ship with corresponding source code, so the freedoms cannot be stripped away downstream.

Why it matters in mining

Several mining-relevant projects rely on the GPL family. The license ensures that improvements to a tool or firmware flow back to the community rather than being captured by a single vendor. D-Central's own DCENT_OS, Toolbox, and DCENT_axe work is released under GPL-3.0, meaning anyone can inspect, audit, and rebuild the code that runs on their hardware.

GPLv2 vs GPLv3

GPLv2 (1991) is concise and remains common in legacy projects such as the Linux kernel. GPLv3 (2007) adds explicit patent grants, anti-tivoization terms preventing hardware locks from defeating the right to run modified code, and clearer internationalisation. The two versions are not directly compatible unless a project is licensed "GPLv2 or later."

The GPL is enforced through ordinary copyright law: by attaching conditions to the right to redistribute, it makes the code and its freedoms legally inseparable. For the underlying philosophy see copyleft, and contrast it with a permissive license, which imposes far fewer obligations on those who reuse the code.