This is one possible form of a semantic web browser -an RDF browser, written by Tim Berners-Lee and the Tabulator team, and widgetized by Opera.
To make RDF access easy on a platform which is open to everyone with a website (or, hopefully, a computer) program in.
To demonstrate the use of Web architecture and Semantic web architecture as they should be used
To throw up problems with the above, for experience for the W3C TAG
To find problems in general implementations or usage which need to be corrected or brought out in best practices documents
To find and design new breadcrumb protocols, conventions by which pointers are left and followed in the Semantic Web so as to make classes of problem solvable