Incubator serves as a platform where anyone can build up a community in a certain language edition of a Wikimedia project (Wikipedia, Wiktionary, Wikibooks, Wikinews, Wikiquote and Wikivoyage) that does not yet have its own subdomain, provided that it is a recognized language. These so-called "test wikis" on Incubator can be used like any other real wiki. When the community desires so, they can request to move to an own subdomain through the [$meta requests for new languages] process. The decision is made by the Language committee.
Wikimedia Incubator is unique in the sense that it is not a real content project like Wikipedia, the free encyclopedia, nor an organizational project like Meta-Wiki, which coordinates the different Wikimedia Foundation projects.