Development policy

The development policy defines how Wikimedia software is developed and maintained. This includes MediaWiki core, the bundled skins and extensions, as well as other skins and extensions that are deployed on Wikimedia Foundation wikis.

High-level
All Wikimedia engineering endeavors are guided by the Architecture principles.

Creation of new services that external to MediaWiki, should follow the Services guideline.

Runtime support
Changes to PHP support in MediaWiki core or components bundled with official MediaWiki releases, must follow the Support policy for PHP.

Code review
Privileged Gerrit users must follow the Gerrit privilege policy when exercising their +2 rights.

Implementation policies

 * Changes to MediaWiki core that deprecate or remove aspects of the public PHP interface, must follow the Deprecation policy.
 * PHP's built in serialization mechanism (the  and   functions) should not be used for data stored (or read from) outside of the current process (RFC T161647). See also the relevant section of the PHP coding convention.
 * Database queries and schema changes must follow the MediaWiki database policy.