Fifteen years after the launch of the World Wide Web and five years after the start of the Semantic Web, the web of documents is well deployed and work on the web of data is taking off steadily. This talk will discuss the challenges and deployment paths, as well as the the Semantic Web concepts and progress to date. Tim Berners-Lee is the director of the World Wide Web Consortium, senior researcher at MIT’s Computer Science and Artificial Intelligence Laboratory, and professor of computer science at Southampton School of Electronics and Computer Science.