Browser Statistics Month by Month

From the statistics below, you can see that Internet Explorer and Firefox are the most common browsers.

2009 | IE7 | IE6 | IE8 | FireFox | Chrome | Safari | Opera
May 21.3% 14.5% 5.2% 47.7% 5.5% 3.0% 2.2%

http://www.w3schools.com/browsers/browsers_stats.asp

June 2009
Internet Explorer 7.0 30.54%
Windows XP 69.09%
1024x768 38.04%

http://www.w3counter.com/globalstats.php