LGPLcompatible

LGPL-compatible refers to licenses that can be legally combined with software released under the GNU Lesser General Public License (LGPL) under the terms of both licenses. A license is considered LGPL-compatible if its terms permit the creation and distribution of a combined work that includes an LGPL-licensed library without imposing obligations that contradict the LGPL, and if the overall distribution remains compliant with the LGPL’s requirements for notices, source availability, and the user’s freedom to modify and re-link.

Key considerations include the specific version of the LGPL involved (for example, LGPL v2.1 vs v3) and the method of linking (dynamic versus static). Compatibility is determined by the exact wording and conditions of the licenses, and in some cases licenses are explicitly declared compatible by the Free Software Foundation or through recognized licensing practice. In many cases, permissive licenses are treated as LGPL-compatible for libraries, allowing code under those licenses to be linked with LGPL-covered libraries, subject to preserving LGPL obligations for the library portion.

Implications for developers include understanding that using an LGPL-compatible license for a library does not eliminate copyleft duties. When distributing a combined work, the library portion must comply with the LGPL’s requirements, such as providing access to the library’s source code and allowing relinking or modification of the library by downstream users.

Limitations include that compatibility is not universal or universal across all license variants, and it does not equate to full license interchangeability. For authoritative guidance, consult official LGPL compatibility statements from the Free Software Foundation and, when in doubt, seek legal counsel.