We know that operating systems bring in quite a bit of money, and that Windows is a cash cow for Microsoft, but what are the numbers anyway? Well, it turns out that worldwide operating system revenue totaled $30.4 billion in 2010, a 7.8 percent increase from 2009, according to Gartner.

Linux server and Mac OS were the fastest-growing segments in the server and client categories, respectively, while Microsoft maintained its leading position in the overall OS pie, with 78.6 percent market share in terms of revenue. IBM took second place with 7.5 percent revenue share and HP took third with 3.7 percent revenue share. Oracle was fourth (2.6 percent), Red Hat was fifth (2.0 percent), and Apple was sixth (1.7 percent).



Oracle entered the market by acquiring Sun Microsystems (and its Solaris business) for $7.4 billion in April 2009. Disregarding Oracle, which Gartner awarded 0.00 percent of the market in 2009, Microsoft gained the most from 2009 to 2010, moving up an additional 0.7 percentage points. Everyone else increased or decreased by either 0.1 percentage points or 0.2 percentage points.

Microsoft's Windows client business had higher growth at 9.2 percent, compared with its Windows server business at 7.5 percent growth. A new wave of PC refreshment after the economic recession was the major reason for the better-performing Windows client business (if you haven't yet heard, Windows 7 is on a roll). The software giant is going to try to pull the same thing off with Windows 8, but something tells us it won't be so easy.

"Generally, client OSs outperformed server OSs and grew 9.3 percent in 2010, while the server OS segment grew 5.7 percent," Matthew Cheung, principal research analyst at Gartner, said in a statement. "The long-pending demand for PC refreshment was unleashed as the economy stepped out from the economic turndown, which drove growth of client OSs."