PHP has completed its transition to the BSD 3-Clause license, retiring the long-standing PHP License 3.01 after a multi-year review.
Ben Ramsey confirmed the update in a notice to the Open Source Initiative’s license-review mailing list on behalf of the PHP Group. The notice states that the PHP License 3.01 has been voluntarily retired and is no longer in use. The PHP project also discourages its use for new projects.
This change follows last year’s proposal to replace PHP’s custom license with a standard permissive license. The process has concluded with PHP adopting the Modified BSD License, also known as the BSD 3-Clause license, as its new license.
Additionally, PHP License 3.0 has effectively been retired as well, as the Open Source Initiative lists it as superseded by PHP License 3.01. With both licenses now retired, PHP has ended its use of custom licensing terms that had been in place for decades.
The change also impacts Zend Engine licensing. The original proposal described the new license as PHP License version 4 and Zend Engine License version 3, replacing the previous split between PHP’s license and the separate Zend Engine License.
What is the main idea behind all these? In short, the licensing change simplifies compliance for downstream projects and Linux distributions. The previous PHP License included naming restrictions specific to PHP, and the Zend Engine License was not OSI-approved. An earlier RFC also noted that neither license was GPL-compatible.
By adopting the BSD 3-Clause license, PHP now uses a widely recognized permissive license with clearer compatibility and broader tooling support. For distributions, package maintainers, and projects embedding or redistributing PHP-related code, this change removes ambiguity around PHP-specific terms and aligns the project with a standard open-source license.
The retirement notice also requests that the Open Source Initiative update its license listings to mark the PHP License 3.01 as retired. This formally concludes the licensing transition proposed in 2025 and confirms BSD 3-Clause as PHP’s current license.
