GPL v2.0: The Original Copyleft License
Learn about the GNU General Public License v2.0 (GPL-2.0), the original strong copyleft license used by the Linux kernel and many foundational open source projects.
Detailed Explanation
GNU General Public License v2.0
The GPL-2.0 is the second version of the GNU General Public License, published in 1991. It remains one of the most important open source licenses, notably as the license of the Linux kernel.
Historical Significance
GPL-2.0 was the license that established the copyleft concept in software. Richard Stallman and the Free Software Foundation created it to ensure that software freedoms — the freedom to run, study, share, and modify software — would be preserved in all derivative works.
Key Characteristics
| Attribute | Value |
|---|---|
| SPDX Identifier | GPL-2.0-only |
| Type | Strong Copyleft |
| Patent Grant | No explicit grant |
| Copyleft | Yes (strong) |
Differences from GPL-3.0
- No explicit patent grant — GPL-2.0 has an implied but not explicit patent license
- No anti-Tivoization clause — Hardware can restrict running modified GPL-2.0 code
- Narrower compatibility — Fewer licenses are compatible with GPL-2.0 vs GPL-3.0
- Simpler text — GPL-2.0 is shorter and simpler
The "or later" Clause
Many GPL-2.0 projects include the phrase "or any later version," meaning the code can also be used under GPL-3.0 or future GPL versions. The Linux kernel famously does NOT include this clause, meaning it is strictly GPL-2.0-only.
When Is GPL-2.0 Still Used?
GPL-2.0 is mainly used for legacy projects that were licensed before GPL-3.0 was released in 2007. New projects typically choose GPL-3.0 unless they have specific reasons to prefer the older version.
Use Case
Understanding the license of the Linux kernel, contributing to GPL-2.0 projects, or evaluating the legal implications of using GPL-2.0 libraries in your software stack.