Wikia is an open source Internet search engine, to which the community can contribute to content, relevance and rankings of the search engines result pages.
Just not like Google, Yahoo or Msn that are automatic search engines, Wikia is a Human Search Engine.
It was founded in 2004 and received investment money from Amazon and Bessemer Venture Partners.
Search battle is going to be exciting for all of us in 2008, thanks to the war between Wikia-Wikipedia and Google-Google Knol.
SEO and SEM is already ready as you can see here.