Definition#8
from "Wales giving up on Wikia Search"

1.Wikia
(formerly Wikicities) is a free web hosting service for wikis (or wiki farms) operated by Wikia, Inc., a for-profit Delaware company founded in late 2004.[3]
Wikia was founded by Jimmy Wales and Angela Beesley, respectively the Chairman Emeritus and Advisory Board chair of the Wikimedia Foundation

2.Wikimedia Foundation
The Wikimedia Foundation, Inc. is a non-profit charitable organization headquartered in San Francisco, California, United States, and organized under the laws of the state of Florida, where it was initially based. It operates several online collaborative wiki projects including Wikipedia, Wiktionary, Wikiquote, Wikibooks (including Wikijunior), Wikisource, Wikimedia Commons, Wikispecies, Wikinews, Wikiversity, Wikimedia Incubator and Meta-Wiki. Its flagship project, the English-language Wikipedia, ranks among the top ten most-visited websites worldwide.

3.Wikia Search
was an open source project run by Wikia to create an editable, transparent, and free search engine. It closed down in April 2009.

4. Wikianswers
Wikianswers is a site where you can ask questions and give answers. We're aiming to create the best answer to any question.

5. Google SearchWiki
SearchWiki is a Google search feature which allows logged-in users to annotate and re-order search results. The annotations and modified order only apply to the user's searches, but it is possible to view other users' annotations for a given search query.