Karsten Hoffmeyer is a MediaWiki developer and system administrator who has contributed a great deal of work to the internationalization and extension documentation efforts at MediaWiki.org. He is also active at, and provides a great deal of expertise and input at WikiApiary. He is involved with Fundraising-Wiki and WikiHoster.net and is a sysop of WikiIndex. Karstens' username is kghbln.
Karsten translates system messages at TranslateWiki.net. Additionally he is the main editor at Semantic MediaWiki.org. He also is active on SemanticWeb.org and UniversalEditButton.org. In the Free Software Directory he sees to it that everything with the listings of MediaWiki and Semantic MediaWiki is up-to-date.