The first U.S. grid to allow multiple virtual organizations to share resources in a common infrastructure ended its successful two-year run on September 1. Researchers from several scientific fields used Grid3 to test their new grid-enabled applications, learn how to operate and work within a grid environment, and produce scientific results.

"New discoveries in astrophysics, simulations in particle physics, earthquake engineering optimizations and analyses of protein sequences in biology all benefited from extended use of Grid3 resources," said Fermilab's Ruth Pordes, one of the Grid3 coordinators. "These results would not have been possible without interfacing individual projects' computing resources to Grid3's common infrastructure."

Grid3 was initially created to demonstrate specific technologies at the Supercomputing 2003 conference. It proved so successful that operation was continued well after the conference, to the benefit of participating scientists. Grid3 represented breakthrough collaboration between the National Science Foundation-funded GriPhyN and iVDGL projects, the Department of Energy's Office of Science-funded PPDG project, the U.S. ATLAS and U.S. CMS particle physics experiments and the Condor and Globus teams—collaboration that will continue with the Open Science Grid infrastructure.

"When Grid3 was at its largest it included almost 40 sites," said Rob Quick from the iVDGL Grid Operations Center at Indiana University, which acted as the central operations center for Grid3 and will do the same for the Open Science Grid. "Most of those sites have moved to the OSG, which began production in May. With 43 sites and 15,000 CPUs now on the OSG, it was the right time to make the transition."

Grid3 was essential to U.S. participants in the ATLAS and CMS particle physics experiments at the Large Hadron Collider in Switzerland, who used the infrastructure to produce millions of simulated particle physics events. Physicists use the simulated data to determine how the brand-new detectors will respond to different types of interactions—an essential step in making discoveries about the nature of the universe. ATLAS and CMS physicists will use the OSG to continue to produce simulated data, and to analyze real data once the LHC starts running in 2007.

"Grid3 was the first example of a nationwide grid with shared resources that experiments could draw on to do major production," said Paul Avery from the University of Florida. "It really taught us how to run a multi-user grid environment, and has paved the way for us to transition smoothly into the Open Science Grid."

Learn more at the Grid3 and Open Science Grid Web sites.