Based on recent events over there at the Shangri-La Monkey House known as Microsoft (they won't completely support W3C Cascading Style Sheets), it is more important than ever to support open source products.
Mozilla is a web browser, mail reader, and rss aggregator (if you also install NewsMonster) that is free to you. What is more important in the really big picture is that if Microsoft IE is allowed to rule the browser market, they can (and will, by the looks of the c|net article) also control the standards on which all Internet activity is controlled. This is a big deal.
If the most used browser wont support something like css (a common and important tool for creating the look of a Web page - [X]Press pages are based on css) it forces third party software developers to create products based on a Microsoft standard rather than a standard for the industry at large.
If you wanted to know what is at the heart of all the fuss about law suits and Microsoft, this is it and if you enjoy the Internet, it is best to pay attention.