Wikihow is a wiki-based community with a database of how-to guides. All of the site's content is licensed under Creative Commons (by-nc-sa); and the site uses a modified version of MediaWiki 1.9.3. The site started as an extension of the already existing eHow website, and has evolved to host over 39,000 how-to articles. wikiHow's mission is to build the world's largest how-to manual and help it grow. In September 2007, wikiHow had 7.86 million unique readers.