At the Berlin Hackathon 2011, MediaWiki developers come together, squash bugs and write crazy new features. Main topics include improving the wikitext parser, richt text editing, interactive maps, mobile and offline access among others. The event will be centered on coding, but there will be several short presentations every hour or two, as well as morning and evening sessions. Presentations will be scheduled ad-hoc and announced on twitter using the hashtag #mwhack11.