The W3C create web standards. These standards make sure that in every browser, the website you view will look the same. These standards specify the syntax of each command, where they can be used, what modifiers you can use with them, and so on, so forth. IE has never played well with standards. IE has these quirks that means you can't do specific things that the standards say you can, and every other browser says you can. The IE team has used the fact they have a significant market share to slow down web development by refusing to implement certain languages that would make the web more accessible and better in terms of usefulness.
As a web developer, I end up having to make a site with interactivity and amazing features... and then a second site that works in IE. A dulled down, worse version without any of the HTML5 or CSS3. A site with limited functionality, because that's all IE will do for me.
I hate IE because it makes me take up twice my time to make both a standard and a mediocre version of a site, the mediocre version not even standards compliant by W3C's checker because if I do it right, IE can't display it properly.
SOURCE: FireFox vs. Internet Explorer? on Yahoo! Answers
So, that's the technical end of it.
From a user perspective (and I've been using Firefox since Version 2), it's just a cleaner web browsing experience, and once they introduced Sync -- I'm a "lifer" now.
I have my main desktop box running XP Pro at home, my personal laptop, and my company laptop, and using Sync on the three Firefox installs keeps all of my Bookmarks, Preferences, and open Tabs sync'd up across all three machines. Further, there are options to also sync up Add-ons, Passwords, and browser History.
If I create a new Bookmark using any one of the three computers, that Bookmark will be available on all of them in a matter of moments. Using Sync I can intentionally leave a tab open on my company laptop, go home, sit down at my main desktop, and click "Firefox > History > Tabs From Other Devices" to pull up exactly what I was looking at in my office.
My wife can be browsing at home, see something she wants to discuss, call me, and I can use the same process on my office laptop to pull up the exact web page she's looking at in real time.
I've really found the functionality offered by Firefox to be simply unbeatable, and "simply" is the applicable descriptor, as no aspect of using it requires that the user be a guru.
But how user friendly is it to those of us with impearred brainz?
I can’t seem to find anything to read that I can understand, and I don’t want to download something that will mess me up down the road.
Thank you for that, HKMk23,
Will be looking into Firefox in the next couple of days.
Must procrastinate first. :)