These are the stats for April 2014.
Windows 438,672 74.3 %
Linux 106,646 18 %
Macintosh 22,317 3.7 %
BSD 17,527 2.9 %
Unknown 3,510 0.5 %
Java Mobile 678 0.1 %
Unknown Unix system 205 0 %
Nintendo Wii 123 0 %
BlackBerry 27 0 %
Sun Solaris 25 0 %
Opera No 348,157 59 %
Google Chrome No 104,095 17.6 %
Firefox No 89,239 15.1 %
Safari No 28,787 4.8 %
LG (PDA/Phone browser) No 10,283 1.7 %
Mozilla No 3,972 0.6 %
MS Internet Explorer No 2,903 0.4 %
Konqueror No 482 0 %
Android browser (PDA/Phone browser) No 477 0 %
ELinks No 452 0 %
Glancing over at the IE version breakdown, I noticed something interesting about IE6:
Msie 10.0 No 174 0 %
Msie 9.0 No 277 0 %
Msie 8.0 No 736 0.1 %
Msie 7.0 No 232 0 %
Msie 6.0 No 1,480 0.2 %
Msie 5.0 No 1 0 %
Msie ? No 3 0 %
NB Otter is probably counted as Chrome or Safari. So is Opera 15+.