Code:
Operating System Requests Percent
Windows 3,469,687 81.78%
Mac 327,753 7.73%
iPhone 116,311 2.74%
Linux 107,158 2.53% (including Android)
iPad 31,506 0.74%
BlackBerry 17,028 0.40%
SymbianOS 7,926 0.19%
DoCoMo 449 0.01%
SunOS 368 0.01%
FreeBSD 347 0.01%
OpenBSD 26 0.00%
Total 4,242,653 100.00%
SOURCE:
http://stats.wikimedia.org/archive/squid_reports/2011-03/SquidReportOperatingSystems.htm