The Sun Grid runs on Opteron-based systems running the Solaris 10 operating system. Sun expects clients to use the grid to run Java- and C++-based software that can take advantage of a grid environment.

Sun isn't disclosing the number of CPUs available to users of the service, other than to say it's in the thousands.

The largest commercial Sun Grid user so far is Virtual Compute Corp., a Cypress, Texas-based firm that provides high-performance computing services.

CEO Edward Hayes said the company bought more than 1 million hours of compute time last fall and has recently been running a customer's seismic survey data to create a 3-D rendering of what's underground.

Sun intended to launch the public grid early last year, but it faced delays, including U.S. State Department concerns about making such massive compute resources widely available.