What category does GNU General Public License belong to?

GNU General Public License belongs to the "Software Development" category in personal knowledge management and productivity.

What are the key topics related to GNU General Public License?

Key topics related to GNU General Public License include: software-engineering, collaboration, tools.

What are alternative names for GNU General Public License?

GNU General Public License is also known as: GPL, GPL License, GNU GPL.

GNU General Public License

A copyleft free software license that guarantees users the freedom to run, study, share, and modify software, requiring derivative works to be distributed under the same terms.

Also known as: GPL, GPL License, GNU GPL

Category: Software Development

Tags: software-engineering, collaboration, tools

Explanation

The GNU General Public License (GPL) is a copyleft free software license created by Richard Stallman for the GNU project. First released in 1989, the GPL ensures that software remains free by requiring derivative works to be distributed under the same license. It has become the most widely used free software license, covering the Linux kernel, GCC, and thousands of other projects.

The GPL's key innovation is copyleft: using copyright law to ensure freedom rather than restrict it. Unlike permissive licenses like MIT or BSD, the GPL requires that modified versions also be open source, preventing proprietary forks. This 'viral' nature is controversial in business contexts but ensures that software freedom propagates through all derivative works.

The license has evolved through three major versions. GPLv1 (1989) established the foundational principles. GPLv2 (1991) added the 'Liberty or Death' clause, preventing distribution if legal restrictions would prevent passing on the same freedoms. GPLv3 (2007) addressed modern concerns including patent protection and anti-Tivoization provisions that prevent hardware restrictions on modified software.

Core requirements of the GPL include making source code available, ensuring derivatives use the GPL (copyleft), prohibiting additional restrictions beyond the license terms, and including the GPL license text with distributions. The GPL family also includes the LGPL (Lesser GPL), which allows proprietary linking for libraries, and the AGPL (Affero GPL), which extends copyleft requirements to software accessed over a network.

Notable projects licensed under the GPL include the Linux kernel (GPLv2), GNU Compiler Collection (GCC), WordPress, Drupal, GIMP, and Inkscape. The license remains foundational to the free software movement's goal of ensuring software freedom for all users.

Related Concepts

Open Source

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