How to Check Your Website with Multiple Browsers on a Single Machine (Cross-Browser Compatibility Checking) (thesitewizard.com)

We all know the importance of checking our web pages with multiple browsers, especially when we are designing a new layout for a website. The number of extant browsers we need to check with are enormous: Internet Explorer (IE) 6, IE 5.5, IE 5.0, Netscape 7.X (ie, Mozilla 1.0.X), Netscape 6.X (or Mozilla 0.9.X), Mozilla 1.3.X (and above), Opera 7, Opera 6/5, Netscape 4.X, IE 4.X and so on. And then there are the different platforms: Windows, Macintosh (Mac), Linux, etc. The problem for most people is that multiple versions of certain browsers cannot co-exist with each other, the most notable example of this is IE for Windows. Unless you are privileged to have multiple computers, this presents a certain difficulty for the average webmaster. This article suggests some ways for you to run multiple versions of multiple browsers on one computer.

Note that this article is written primarily from the point of view of a person using Windows (the majority of people reading this article), although it does address the issue of Mac browsers and Linux browsers as well.