Developers are the people contributing to the code ofMediaWiki software.They commit changes to the centralGit repository by pushing changes for review inGerrit where the latest copy of the software is stored.Developers includepaid Wikimedia Foundation staff and volunteers.Anyone can submit a patch forreview after creating aDeveloper account (but only maintainers can merge it).For statistics or names, seeDevelopment statistics.
Developers are not to be confused withsystem administrators, who are people havingshell or root access to Wikimedia Foundation servers, where the code repository is stored.They might not really be developers; in many cases they rarely use their commit access, or if they do, only to maintain non-MediaWiki things in the repository.
Amaintainer of a specific project (including MediaWiki core or an extension) has+2 access to the relevant Git repository, so that they can merge patches others submitted.They usually regularly respond to bug reports and changeset review requests.A list of maintainers are kept atDevelopers/Maintainers.
Historically, developers also managed Wikimedia Foundation servers (now managed by system administrators).Beforebureaucrat andsteward groups were created, developers were the only ones able to promote and demote sysops, and lock user accounts (before the "block" feature of MediaWiki existed).Thus they had an important role in theWikimedia power structure.
From April 2006 to March 2012,Subversion was used.Only people withSubversion commit access (which must be approved by SVN administrators) could submit code changes.Code changes submitted to Subversion was merged to MediaWiki codebase immediately (though they could only be manually deployed to Wikimedia wikis by a system administrator), and may have been reviewed by"coders" before they are deployed.In January 2013, the MediaWiki SVN repository was made read-only.All active projects have moved to Git.