Any site designer knows that testing your web site across multiple browsers is key. But not only has the market become very fragmented regarding the number of browser, but there are also several popular VERSIONS of browsers running around as well -- each with their own quirks. Here are some current browser stats:
According to http://www.w3schools.com/browsers/browsers_stats.asp (January 2007)
- IE7: 13.3%
- IE6: 42.3%
- Firefox: 31.0%
- IE5: 3.0%
- Safari: 1.7%
- Mozilla: 1.5%
- Opera: 1.5%
According to http://www.webreference.com/stats/browser.html (January 2007)
- IE7: 13.12%
- IE6: 31.37%
- IE5: 1.71%
- Firefox: 28.79%
- Safari: 2.5%
- Mozilla: 2.04%
- Opera: 1.65%
Based on this, IE6 & 7, and Firefox should be in your testing regimen. If you further break down the Firefox users you'll see that you should probably also test Firefox 1.5 & 2.0 since both have a strong following. On the other hand, the differences in standards support between Firefox 1.5 & 2.0 is not that great.
What do you think should be tested?