PSFLlicensed

PSFLlicensed refers to software released under the Python Software Foundation License (PSFL). The PSFL is a permissive open-source license associated with the Python ecosystem and related projects. It grants broad rights to use, copy, modify, merge, publish, distribute, sublicense, and sell copies of the software.

Key terms of the PSFL include preserving the original copyright notices and license text in redistributions, and documenting significant modifications. The license does not restrict proprietary use or require derivative works to be licensed under PSFL, meaning you can integrate PSFL-licensed code into larger works that are distributed under different terms, as long as the PSFL portions retain their notices and license requirements. The PSFL also includes a disclaimer of warranties and limits liability.

Trademark and endorsement provisions prevent using the Python Software Foundation’s name or the Python name itself to promote or endorse products derived from PSFL-licensed software without prior written permission. This helps avoid implying official PSF support for third-party derivatives.

Compatibility and deployment considerations: because PSFL is permissive, it generally supports inclusion in a wide range of projects, including commercial software. However, when combining PSFL-licensed components with code under other licenses, redistributors should verify that the combined distribution complies with all applicable terms, especially for the PSFL portions.

Identifying PSFL licensing typically involves checking the project’s license file or header, often labeled LICENSE or COPYING and explicitly referencing the Python Software Foundation License. High-profile examples include Python itself; many PSF-affiliated projects use the PSFL for its flexibility and clarity.

In summary, PSFLlicensed software enjoys broad reuse rights with standard attribution, trademark protections, and clear terms for redistribution and modification.