I had the opportunity today to read the Gartner Group's May 3, 2006, forecast for the worldwide personal computer market by operating system for 2001-2010 (Document ID Number: G00139385).  For those of you who haven't seen it, here are some of the highlights:

• Windows XP will be running on more than 70% of the world's PCs by the end of 2006.
• By the end of 2007, Windows Vista is expected to be running on less than 6% of the machines in the world.
• About 16% of all PCs sold worldwide ship with Linux, DOS, or no operating system.
• The initial OS installed on new PCs, if it isn't Microsoft Windows, is often replaced by a pirated copy of Windows.
• Once put into service, over 95% of all PCs are running windows regardless of the OS they shipped with, and only 2% end up running Linux.
• Gartner does not expect that Apple's Boot Camp will make Macs any more attractive to corporate customers outside the traditional education, graphic arts, and video production markets.
• Apple's share of the PC market is expected to remain flat in 2006, but Apple's Mac OS share is expected to increase by 0.1% to 0.3% in mature markets through 2006.

Below is a chart of the installed base of operating systems worldwide in 2006:

Apple's market share is the highest in the United States (4.3%) and the lowest in the Asia/Pacific region (0.7%).  Worldwide it's only 2.4%.  Linux has about 1.7% of the worldwide market, with the lowest share in the United States at 0.7% and the highest in Western Europe and the Asia/Pacific regions at 2.0%.

It's interesting to note that the worldwide share of Windows 9x is still 5.8% of the market.  Windows NT is only at 0.7%, Windows 2000 Professional at 16.6%, Windows XP Pro at 37.6%, and Windows XP Home at 35.1%.