IBM systems account for <A HREF="http://www-03.ibm.com/press/us/en/pressrelease/19895.wss">240 of the 500 most powerful supercomputers</A> in the world and more than half the total processing power according to the just-released TOP500 Supercomputer Sites list. IBM's Blue Gene/L developed and installed at Lawrence Livermore National Laboratory tops the list with an unprecedented sustained performance of 280.6 Teraflops, or trillions of floating point calculations per second.