Version lifecycle/en

MediaWiki operates on a "continuous integration" development model, where software changes are pushed live to Wikimedia web sites such as Wikipedia on a regular basis.

In theory, new major releases are issued on a half-year basis, and release branches continue to receive security updates for up to a year as of first release. Due to time constraints and rapid refactoring of the code base, we cannot support obsolete releases forever, and security and critical updates are not applied to releases which have reached their end of life status.

The release manager strongly recommends that wiki operators subscribe to the  mailing list, which receives notification of all releases, and ensure that their wiki runs the most up to date version of the software possible. These announcements are also posted to  and.

Versions and their end-of-life
Versions included in the above table that are marked as obsolete as well as versions not listed at all will not receive any security fixes. They may contain critical security vulnerabilities and other major bugs, including the threat of possible data loss and/or corruption. The release manager has also issued a strong recommendation that only versions listed above as current version or legacy version should be used in a production environment.

Release policy

 * Every point release will include updated i18n files as well as any bug fixes. No new features will be back-ported to point releases and support doesn't include extensions in general, see below (e.g. doesn't support current LTS).
 * A major release will be made every six months.
 * A long term support release (LTS) will be made every two years. There will be a one-year overlap in LTS support. For example, 1.23 was supported until May 2017. 1.27 was released the year before that so that people had it available as an LTS to move to and a year to make the transition.
 * Release notes will continue to be the basis for seeing what has changed. Because of the nature of a volunteer-driven project, it isn't possible to say with any certainty what will happen in the next 6-12 months.
 * To mitigate the problem of release notes, we will publish a list of new features in the upcoming LTS relative to the last LTS six months before it comes out. This means that about the time when 1.26 came out, an announcement was made for 1.23 users letting them know what changes they could expect in 1.27.

Release timeline
This timeline is a schedule for what needs to happen before the release of a new version. The date of the actual release is given here as T (for "time" of release) and the suffix -# (for “number of weeks prior to release”).

Extension lifecycle management
Most MediaWiki installation include a significant number of extensions (WMF MediaWikis often around 80 extensions). Managing the maintenance bug fixing of extensions and choosing the right version of an extension in cases where the HEAD development version relies on features not yet available in stable or oldstable MediaWiki core, is a major challenge for all maintainers of MediaWiki installations.

Extension maintainers are therefore strongly encouraged to maintain a git tag or branch for their version corresponding to the release tag the stable and oldstable version. An initial version, that simply points to the state of the code at the time of the release may be created centrally. However, it is the responsibility of the extension maintainer to fix bugs not only in HEAD but also in the oldstable and stable versions. If the extension works with all of oldstable, stable and HEAD, this requires only to update the tags. However, if some changes are specific to later versions, the lifecycle rule require that branches are created and individual merges of the bugfix to each branch be made.

The goal of these rules is that people or organizations installing MediaWiki can rely on installing the newest release of a version and matching extensions by a simple method, e.g. for 1.20.x core by referring to REL1_20 in git.