Current collaborative software usually have no or limited support for ad-hoc collaboration. SharedMind supports synchronous collaboration, i.e. real-time collaboration, and asynchronous collaboration, i.e. the merging of local instances of a document modified by different users after dis- and reconnects to a group of collaborators. SharedMind is completely decentralized and supports ad-hoc collaboration for interconnected (sub)groups. It demonstrates the confluence of social media and tools for computer supported collaborative works.