Like many designers, I am constantly having to check that the changes I make to my website work in multiple browsers.  In my case I focus on the main options available - Internet Explorer (IE), Mozilla FireFox, Google Chrome, Safari and Opera.  In the case of IE, you can only have one version installed by default and this is the latest version (at the time of writing, Version 8).

I have installed two smart little products on my desktop and Joomla! websites to help me win this battle.

Installing Multiple IE from Tredosoft, which can be installed on Windows XP (in my case, I use a Virtual Machine with Windows XP) and allows all the older versions of IE to run and be used for testing.

You should note the disclaimer near the download link on their landing page that states the product is no longer being developed, but for testing of websites against IE6, this works very nicely.

Combine Multiple IE with the Joomla! extension Internet Explorer 6 Warning Update, and your Joomla websites will very clearly be advising those users still suck with IE6, that they need to update their browser!