Xserve

Xserve was a line of rack unit computers designed by Apple Inc. for use as servers. When the Xserve was introduced in 2002, it was Apple's first designated server hardware design since the Apple Network Server in 1996. (In the meantime, ordinary Power Macintosh G3 and G4 models were rebranded as Macintosh Server G3 and Macintosh Server G4 with some alterations to the hardware, such as added Gigabit Ethernet cards, UltraWide SCSI cards, extra large and fast hard drives etc. and shipped with Mac OS X Server software.) It initially featured one or two PowerPC G4 processors, but was later switched over to the then new PowerPC G5, and subsequently switched again to two quad-core Intel Nehalem microprocessors.