| Latest version | 3.01 |
|---|---|
| Publisher | The PHP Group |
| SPDX identifier | PHP-3.01 |
| Debian FSG compatible | No[1][2] |
| FSFapproved | Yes[3] |
| OSIapproved | Yes[4][5] |
| GPL compatible | No[3] |
| Copyleft | No[3] |
| Website | www |
ThePHP License is theopen-source license under which thePHP scripting language is released. The PHP License is designed to encourage widespread adoption of the source code. Redistribution is permitted insource orbinary form with or without modifications, with some caveats.
Version 3 of PHP used adual license—PHP 3's source is available under either the PHP License or theGNU General Public License (GPL). This practice was discontinued as of PHP 4, with PHP's developers citing the restrictions on reuse associated with the GPL'scopyleft enforcement as being the reason for dropping it.[7] TheZend Engine, the core of the PHP interpreter, is separately licensed under the similar Zend Engine License,[8] which contains similar naming restrictions to the PHP license (applying to the names "Zend" and "Zend Engine"), and a clause requiring advertising materials to mention its use.
The PHP License is anopen source license according to theOpen Source Initiative, and a non-copyleftfree software license according to theFree Software Foundation.[4][5][3] The license isGPL-incompatible due to restrictions on the usage of the termPHP.[3]
Debian maintainers have had a long-standing discussion (since at least 2005) about the validity of the PHP license.[9] Expressed concerns include that the license "contains statements about the software it covers that are specific to distributing PHP itself", which, for other software than PHP itself therefore would be "false statements".
Debian has a specific policy for the license (and requires a statement in debian/copyright file when it is used): "The PHP license must only be used for PHP and PHP add-ons."[10]
