We discuss in turn the applications that motivate the development of GT4 and related tools the

four tasks involved in building Grids: design, deployment, application, operations GT4 structure,

including its Web services (WS) and pre-WS components the Globus universe and its various

components GT4 performance, scalability, and functionality testing porting to GT4 from earlier

versions of GT who’s using GT4 likely future directions, and a few words of history.