I’ve noticed more and more that Firefox really rules as a browser. It used to be that when testing web applications, I turned to IE6 first. Most things looked pretty good in IE6, and often were broken or badly formatted in Firefox (or Netscape, or Opera, or Safari, or whatever). However, in recent months, just the opposite is true. Sites generally look good in Firefox, but they look terrible in IE6! And IE7 is not much better. Unfortunately IE6 is still a large portion of the browser market (though Firefox is steadily gaining ground), so I still have to test in it. But for my browsing I will always turn to Firefox.
When browsing and testing in Firefox, I’ve found a number of add-ons that are useful, and one of them is Web Developer (see the dev’s website here). Just today I used it to look at the attributes of a page I was viewing, in order to copy some of the styles into another CSS document. I frequently use it to view all of the cookies set by a page, the colors included, or to highlight various elements. It even includes links (which are configurable) to online validators for HTML, CSS, Section 508, and more. Props to Chris Pederick (here’s his blog) for a great add-on!