DeepaMehta is an open source semantic desktop application based on the topic maps standard. It’s conceptualisation and especially the innovative graph-based user interface have been guided by findings in cognitive psychology in order to provide a cognitively adequate working environment for knowledge workers of all kind. DeepaMehta aims to evolve nowadays’ separated desktop applications into an integrated workspace enabling the user to organize, describe and relate information objects like text notes, external documents and media, browse the web, search databases and create semantic networks—all this in one seamless, semantics-enabled desktop environment.