One of the biggest pain in web development is testing the site rendering on multiple browsers, operating systems and screen resolutions. It is a necessary step that usually involves the use of multiple computers. One of the reasons to need multiple computers (beside testing on different operating systems) is because multiple versions of specific browsers (read IE) cannot be installed on the same computer.
When creating websites with Cascading Style Sheets (CSS) you quickly realize that correctly coded sites break under IE6. IE7 does not have all the CSS bugs fixed which will cause the pages to still render differently than other browsers. Therefore, it is important to have access to multiple versions of IE.
To test the Mac version of Firefox, Safari or Opera you will need a Mac.
I’m not suggesting that your application should work on all the versions of every browser. Not supporting IE4 or Netscape 3 may not be relevant to your site users. Defining the minimum version, browser and screen resolution support will establish a good baseline for cross browser testing. Web usage statistics can help with completing this task.
So here is the light at the end of the tunnel:
How to test with multiple browsers on a single machine
I’ve found two free options and multiple paid (ranging from a few $ to hundreds and thousands $$$). Here are the free tools:
IE NetRenderer allows you to see screenshots of your site rendered by different versions of Internet Explorer (from IE5.5 to IE8). There’s no need to wait to view the screenshots. The Mixed and Difference views display the site rendering differences (ex. IE6 vs. IE8).