PHP License

PHP License

The PHP License is a permissive software license created for the PHP (programming language) distribution and associated extensions, crafted by the PHP Group to govern redistribution and use of PHP source code. It defines terms for modification, redistribution, and attribution, and has been central to discussions involving Free Software Foundation, Open Source Initiative, GNU General Public License, and major projects that interoperate with Apache HTTP Server and Nginx. The license's wording has influenced licensing debates involving entities such as Zend Technologies, Oracle Corporation, Microsoft Corporation, Facebook, Inc., and the Linux Foundation.

History

The PHP License originated alongside the early releases of PHP (programming language) in the mid-1990s, authored by core contributors associated with Rasmus Lerdorf, Zeev Suraski, and Andi Gutmans while collaborating with the PHP Group. Early stewardship intersected with legal counsel from organizations like SUSE and Red Hat during packaging discussions for distributions such as Debian and Ubuntu. As PHP matured through major versions (PHP 3, PHP 4, PHP 5, PHP 7), the license text was revised to clarify redistribution rights, a process that drew commentary from the Free Software Foundation and reviews in academic venues including papers referencing ACM proceedings and analyses by legal scholars at institutions like Harvard Law School and Stanford Law School.

Terms and Conditions

The license grants permission to copy, modify, and distribute PHP source code while requiring preservation of copyright notices and a specific disclaimer of warranty. It includes clauses that address attribution to the PHP Group and restrictions on use of the "PHP" trademark, which intersects with policies enforced by organizations such as World Intellectual Property Organization. The license explicitly disallows certain endorsements or representations of compatibility without consent from the holders, a stipulation that has parallels to clauses found in licenses scrutinized by Open Source Initiative and debated by legal teams at IBM and Google LLC. The waiver of liability and the no-warranty provision mirror statutory formulations discussed in contexts like Berne Convention-related analyses and litigation involving European Court of Justice precedents.

Compatibility and Comparisons

Compatibility with other free and open licenses has been a contentious topic: the PHP License is generally considered incompatible with the GNU General Public License by the Free Software Foundation due to attribution and advertising-like clauses, leading to comparison with the BSD license, MIT License, and Apache License 2.0. Projects integrating PHP components often navigate interoperability questions involving LAMP (software bundle), Composer (software) packages, and extensions built by companies like Zend Technologies and communities such as Symfony. Legal comparisons have been made in reports from firms like Orrick, Herrington & Sutcliffe and in policy whitepapers produced by Open Source Initiative and the Linux Foundation on how license terms affect redistribution in distributions like Debian and Fedora Project.

Adoption and Use

The license covers the core distribution used by millions of deployments involving WordPress, Drupal, Magento, and frameworks such as Laravel and Symfony. Major vendors packaging PHP for operating systems — including Canonical (company), CentOS, Amazon Web Services, and Microsoft Azure — have implemented policies to comply with the license terms. Commercial entities like Zend Technologies and Rogue Wave Software historically offered proprietary extensions and commercial support that navigated the PHP License alongside proprietary terms, in interactions with customers including Facebook, Inc. and Wikipedia operators run by the Wikimedia Foundation.

Criticisms and Controversies

Critiques have focused on perceived incompatibility with the GNU General Public License and concerns over trademark restrictions tied to the "PHP" name, which have sparked debates in communities such as Debian and Free Software Foundation Europe. Legal controversies emerged when distribution policies of vendors like Gentoo and Debian prompted discussions with upstream maintainers, and were analyzed in law reviews at institutions such as Columbia Law School and University of California, Berkeley. Some organizations, including corporate legal teams at Oracle Corporation and Microsoft Corporation, have recommended careful license review before bundling PHP with proprietary systems, a stance that influenced decisions by entities like Apple Inc. and cloud providers such as Google Cloud Platform.

Category:Software licenses