Marlboro, Mass.-based Egenera said its third-generation BladeFrame EX enclosure uses x86-based processors in an integrated, virtualized system that allows computing resources to be allocated to applications as needed.

Liebert, which is a unit of Emerson Network Power, uses a coolant other than water in XD, an approach that it says is more efficient. The cooling technology adds about $300 to $400 per blade server to the cost of rack systems, said Susan Davis, Egenera's vice president of marketing.