The PHP programming language has a long history, and for years it was distributed under its own unique license—the PHP License—alongside the Zend Engine License for certain components. However, the PHP project recently announced a major change: the PHP License has been retired, and all PHP code is now under the three-clause BSD license. This shift wasn't simple; it required extensive coordination. Here we answer key questions about why and how this license change happened, what it means for the PHP community, and the steps taken to ensure a smooth transition.
Why was the PHP license retired?
The PHP license had served the project since its early days, but over time it became a barrier to broader adoption and compatibility. The PHP Group recognized that many open-source projects and companies prefer the widely accepted and simple BSD license, which is more permissive and easier to integrate. By relicensing under the three-clause BSD license, PHP aligns with common open-source standards, reduces legal friction for contributors and users, and makes it easier for other projects to include PHP code without needing to evaluate a custom license. The move also simplifies the overall licensing situation, since previously parts of PHP were under the Zend Engine License as well.
What steps were required to change the license?
Changing the license was far from trivial. The PHP License grants the PHP Group authority to modify it, but that meant each original member of the PHP Group had to be located and provide written consent. This involved tracking down individuals who may not have been active for years. Additionally, Perforce Software—the successor to Zend Technologies—held rights to the Zend Engine License components. They had to formally document their full authority and support for the change, which they did via a legal letter. The project also hired an attorney to review the proposal and advise on potential legal issues. To further ensure community buy-in, a six-month public discussion period preceded the final vote, which passed unanimously.
Who approved the license change?
Three key groups had to give their approval. First, every living member of the original PHP Group had to provide written consent. This was a challenging process because some members had moved on from the project years ago, but each eventually agreed. Second, Perforce Software, which inherited Zend Technologies' rights, had to sign off on the Zend Engine License side—they provided a formal letter confirming their authority and support. Third, the broader PHP community had a voice through a six-month discussion period, after which a formal vote was held. The vote was unanimous in favor of relicensing under the three-clause BSD license.
How did the community participate in this decision?
Community involvement was a critical part of the process. After the preliminary legal groundwork and approvals from the PHP Group and Perforce, the project opened a six-month public comment period. During this time, anyone could raise concerns, ask questions, or propose alternatives. The PHP Group and the hired attorney monitored these discussions to address any legal or practical issues that surfaced. At the end of the discussion period, a formal vote was held among active PHP core developers and contributors. The vote passed unanimously, reflecting strong community support for the transition to the BSD license. This open approach ensured transparency and gave long-time contributors a voice in the final decision.
What does the new BSD license mean for PHP users and contributors?
For most PHP users—developers building websites, frameworks, or tools—the change is seamless. The three-clause BSD license is very permissive: it allows anyone to use, modify, and distribute PHP code, even in proprietary software, as long as they include the copyright notice and disclaimer. The only additional requirement (the third clause) is that the names of contributors cannot be used to endorse derivatives without permission. This is essentially the same level of freedom that many popular open-source projects (like Nginx or Redis) offer. Contributors now submit code under the new BSD license, which simplifies licensing compatibility when incorporating third-party libraries. The transition does not affect existing codebases; they remain under the original PHP License unless actively relicensed by their authors.