LGPLv3

LGPLv3, short for Lesser General Public License version 3, is a free software license published by the Free Software Foundation. It is designed for software libraries, allowing them to be linked with non-LGPL software while preserving the freedom to modify the library itself.

Released in 2007, LGPLv3 successor to LGPLv2.1, it was crafted to align with GPLv3 and address concerns about patents and device restrictions. The goal is to enable broader use of libraries in proprietary software while maintaining a copyleft mechanism for the library code.

Key terms include the rights to use, study, modify, and distribute the library. If you modify the library itself, you must make the modified source available under LGPLv3. When distributing a program that uses an LGPL-licensed library, recipients must be able to replace the library with a modified version, and license notices for the library must be preserved. For static linking, you may need to provide object files or a mechanism to relink with a modified library; for dynamic linking, the programmer’s code generally remains under its own license, while the library continues under LGPLv3. The license also provides a patent grant to recipients and permits “or later” versions if the distributor selects that option.

Compatibility with GPLv3 is a notable feature: LGPLv3 is designed to be compatible with GPLv3, allowing GPLv3-licensed programs to link with LGPLv3 libraries. See also: Free Software Foundation, General Public License.