Tolkien Gateway is a wiki which also uses MediaWiki and GNU FDL, and concentrates on J. R. R. Tolkien and his works. The website states that it is "the largest Tolkien encyclopedia on the net", with over 11,000 articles, over 8,000 images, and over 350,000 edits.
Tolkien Gateway was founded by Hyarion in January of 2003.