Much of the focus on virtualisation centres on the corporate back-office, where IT professionals hope to save money, improve reliability and gain flexibility. They do this by using sophisticated software to create virtual servers, in which the logical server is divorced by a virtualisation layer from the underlying hardware, or virtual storage pools. However, there's also a virtual revolution going on for the virtual desktop.

While most major IT vendors have invested heavily into building or buying virtualisation technology, one in particular has been rolling out services, one after another, always with little fanfare and often surreptitiously. Quietly, that is, unless you compare its stock chart with that of major rivals.

The chart alongside shows Google's relative stock price over three years, compared with that of Microsoft and of the tech index in general. (All three are indexed to the zero line at the start of 2005.)