The Server Market is still dominated by IBM, HP and Dell with combined market share of 74%. However, there are several newer players in the “Other Vendors” category that are designing high density data center specific servers. The traditional vendors do not always dominate the new space and new vendors often emerge when there is a significant shift in the market. The shift to the cloud is causing changes everywhere and the big winners still remain to be seen.
IBM 35%
HP 25%
Dell 14%
Oracle 4%
Fujitsu 4%
Other Vendors 18%
http://www.datacenterknowledge.com/archives/2013/03/01/gartner-idc/