Fandom, previously known as Wikicities and then Wikia, is a free, ad-supported web hosting service that uses MediaWiki version as its hosting engine. Its main focus is wikis related to pop culture such as TV shows, movies and video games.
Fandom was co-founded by Jimmy Wales, who also co-created Wikipedia and the Wikimedia Foundation, and has had several other Wikimedia Foundation board members among its executives. For that reason, it has sometimes been described as the commercial arm of the Wikimedia Foundation. However, there is no official connection between Fandom and either Wikipedia or the Wikimedia Foundation.
In 2020, Fandom released its Unified Community Platform (UCP), which enabled its wikis to again make use of standard MediaWiki after having relied on a heavily forked version for many years.
Some of Fandom's extensions can be found at Wikimedia's official Git repository, and their appropriate extension pages are located at Fandom extensions.
Other extensions are still located in Fandom's own Git repository, in the folder /extensions/wikia/. It is likely that most of the extensions have dependency on Nirvana (found at /includes/wikia/nirvana), the EasyTemplate class (found at /includes/wikia/ folder on Fandom's Git) and/or they might require custom database tables. Some extensions are not compatible with newer versions.
- Fandom Developers — a Fandom wiki for software developers interested in Fandom's version of MediaWiki