Changing the libsensors License
When lm-sensors 2 was written, all the code was placed under the GPL license (version 2), including the library, libsensors. Over time, a number of developers complained to us that this made it impossible for them to link their application to libsensors due to license incompatibilities. Indeed, a library released under the GPL can only be used by code itself released under the GPL. This excludes proprietary tools but also tools released under BSD-style licenses and libraries released under the LGPL, for example.
For a long time we have been ignoring the issue, because it wasn't easy to solve. Basically we needed to get the approval of all copyright holders and preferably all other significant contributors if we wanted to be able to change the license. That being said, the problem was real, so we decided to tackle it still. So we started a 1-year campaign to collect as many approvals as possible from all past contributors to libsensors, ending on July 1st, 2010.
Position of the Copyright Holders
- Frodo Looijaard agrees (2009-06-28)
- Jean Delvare agrees (2009-06-28)
- Adrian Baugh agrees (2009-06-28)
- Mark M. Hoffman agrees (2009-07-06)
Position of the Contributors
- Andre Prendel agrees (2009-07-05)
- Darrick J. Wong agrees (2009-07-09)
- Hans de Goede agrees (2009-07-03)
- Kyösti Mälkki agrees (2009-07-08)
- Mark D. Studebaker agrees (2009-06-29)
- Philip Edelbrock agrees (2009-06-29)
- Rudolf Marek agrees (2009-07-07)
- Bob Schlärmann agrees (2009-09-06)
- Luuk Kleiweg agrees (2009-07-14)
- George Spelvin agrees (2009-06-30)
Actual Licensing Change
As you can see, we managed to get the approval of all copyright holders and no disapproval from any past contributor to libsensors 3. So, a license change is possible, and will happen with the next release of libsensors. As of lm-sensors 3.2.0, libsensors is placed under the LGPL license (version 2.1). Note that this change also applies retroactively to all previous versions of lm-sensors 3. This change does not apply to lm-sensors 2.
Libsensors Licensing Summary
For clarity and completeness, here is a summary of what license applies to each version of libsensors:
| Version | libsensors .so name | License |
| lm-sensors 2.0.0 to 2.7.0 | libsensors.so.1 | GPL v2 |
| lm-sensors 2.8.0 to 2.8.1 | libsensors.so.2 | GPL v2 |
| lm-sensors 2.8.2 and any later 2.x.x | libsensors.so.3 | GPL v2 |
| lm-sensors 3.0.0 to 3.1.2 | libsensors.so.4 | dual GPL v2 / LGPL v2.1 |
| lm-sensors 3.2.0 and any later 3.x.x | libsensors.so.4 | LGPL v2.1 |
