The DOE/SC/Oak Ridge National Laboratory in Oak Ridge, Tenn. operates the third most powerful supercomputer and former No. 1, Jaguar. Ancient compared to the Japanese and Chinese best, the system was built in 2009. UT-Battelle, LLC operates this computer for the U.S. Department of Energy.
The U.S. did have five of the top ten supercomputers and dominated the list of the top 500. And it definitely has the best looking one.
To regain the world title, Oak Ridge National Laboratory is working on a $100 million Cray supercomputer called Titan. It's expected to exceed 20 petaflops when completed in 2012, although the first stage will be ready this year.