In the ever-changing server world, the newest hot idea is the blade server. This is an idea that makes eminent sense-multiple server modules, called blade servers or just blades, are housed in a single chassis,  saving space in the computer center, reducing the required cabling, and improving system management. The older options are to have each server module in a tower, much like an under-desk PC, or to mount them in an open rack, with all the connections leading from the rack. The blade server chassis provides the power supply for the blades, the management system, and the network switch; each blade has its own processor, memory, and hard drive. Diskless blades are also possible in larger blade servers, where the disk storage is external to the blades and shared among them. Interestingly, you can mix and match types of blade servers and the operating systems people use in a single chassis. IBM is the market leader in blade servers, with significant competition from Hewlett-Packard, Dell, and Sun Microsystems.