Server Market
Linux Market Share 25%
Windows Market Share 50%
Strong Support from Computer Hardware Vendors HPQ, IBM, etc. http://h71028.www7.hp.com/ERC/cache/107846-0-0-0-121.aspx?%20ERL=true
Market Share by Revenue
Unix 21B http://www.nwfusion.com/newsletters/servers/2005/0328server2.html
Windows 18.5B http://www.nwfusion.com/newsletters/servers/2005/0328server2.html
Linux ~6B http://www.itfacts.biz/index.php?id=P2438
Mainframe ~3.5B http://www.itfacts.biz/index.php?id=P813
Links
Market share by Linux Distro. http://news.netcraft.com/archives/2004/07/12/slight_linux_market_share_loss_for_red_hat.html
Distributions http://distrowatch.com/
TCO Report http://www.iaps.com/blog/2005/04/2005-linux-vs-windows-tco-bombshell.html

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