In this technical demonstration we present a novel web-based tool that allows a user friendly semantic browsing of video collections, based on ontologies, concepts, concept relations and concept clouds. The system is developed as a Rich Internet Application (RIA) to achieve a fast responsiveness and ease of use that can not be obtained by other web application paradigms, and uses streaming to access and inspect the videos. Users can also use the tool to browse the content of social and media sharing sites like YouTube, Flickr and Twitter, accessing these external resources through the ontologies used in the system. The tool has won the second prize in the Adobe YouGC contest, in the RIA category.