Several public commercial clouds and open source cloud computing software

Cloud computing is usually used to describe the large-scale distributed infrastructure, platform and software services provided by third party, which is a hot topic in IT area in recent year. However, it is disputable in industrial and academic area that what is cloud computing and whether it is a novel technology. This paper attempts to draw a clear picture by the introduction of several public commercial clouds and open source cloud computing software, not to discuss the exactly concept of cloud computing. The commercial cloud computing Amazon EC2 IBM smart cloud Google App Engine and Windows Azure were introduced and the implementation of several open source cloud computing software such as Hadoop Eucalyptus open Nebula and Nimbus were detailed. At last, several representative definitions were showed. The purpose of this paper is that a basic knowledge about cloud computing can be obtained by reading this paper.