The best browser ever!
I've been using FireFox
for a while now. It used to be FireBird when I started, and it's been my
default browser ever since. But every new version surprises me, as well the
constant availability and improvement of all sorts of
extensions to it, as well as a growing number of
themes to make it look even better.
For example, I stumbled across the
Google Toolbar. It even supports features not available in the
Google-provided IE toolbar! Amazing. And I can't live anymore without the
extensible search functionality:

It has a sleek design, way better than aged IE one:
And there's an absolutely must-have extension that allows me to open those
everytime-less-often pages that can only be browsed with IE:

And there's even an ActiveX
wrapper that hosts the Gecko rendering engine (the one behind FireFox,
Mozilla and Netscape) and that implements all the interfaces of the IE
WebBrowser control. This means you can get rid of the buggy-non-standard-old
jscript-aged IE browser for your embedded browser needs!
As if it wasn't enough, Mono has a
Gecko# project in the works! IE is dead. Way
toooo late to make anything useful to it to catch up with the new wave of
internet browsers. I sincerely hope all developers start using FireFox,
deploying it, and making web apps that leverage the power of the latest W3C
standards. For most extranet/intranet applications, you can control the
browser. Go fight for any Gecko-based browser. You'll make yourself a
big favor by avoiding IE quicks. You'll also contribute in forcing
Microsoft to stop toying with the idea that they can control the internet, its
content, and the platform through XAML, Avalon and whatever they invent for
that purpose. Dynamic and useful websites were largely possible thanks to MS
innovation back in the browser wars days. Don't let them abandon that
path. It's the one that benefits us all, just as it did by freeing us from the
even-more-buggy Netscape Navigator 4.
Update: I forgot to mention the most important thing for newcomers: FireFox setup for Windows is only 4.7 MB!!! That's even less the size that Netscape Navigator 3.04 had (5.53 MB)!!! Compare that with the incredibly huge 77.51 MB of IE6+SP1...
There's an interesting article on the revival of the browsers war on XML.com.