William E. Johnston is a senior scientist and advisor to the US Department of Energy, Energy Sciences Network (ESnet). He has a MSc in Mathematics and Physics from San Francisco State University. Bill led the effort to develop new network architecture to accommodate massive data flows from the Large Hadron Collider at CERN to several ESnet sites for storage, processing and analysis. Previously Bill established the Distributed Systems Department and he is also co-founder of the Grid Forum. In his presentation he will discuss how computational and data Grids support the work of the high energy physics community.