"It's actively supported by a cash-rich company."-Untamed
I hope you're kidding. Because the real reason firefox is exploading with popularity is the fact they Microsoft has NOT actively supported their browser. The only thing Microsoft has done is sit on it with patchs to keep it safe (but have failed at that too).
As far as my stats source, I picked one that has had a LONG log history and rather large visitor count.
http://www.w3schools.com/ It's a very reputable source even though they're based in UK. The majority of their visitors are from the US.
Trust me, I'm not blowing smoke up anybody's ass my graph is pretty accurate. If you get the chance to look at some server logs that record unique visitor browser stats then do it, you'll notice the same trend.
I'll admit one thing, that Firefox will NOT replace IE but as it stands there is no chance in hell that IE is going to keep up with Firefox. With as many developers as Firefox has it's just impossible for IE to come up with as many features/advantages. Linux should have done the same thing years ago but it didn't. The majority of Linux developers were young and forced (through school or work) to use Microsoft products, it's a shame that never took off like firefox. Also, Firefox is a crossplatform browser meaning it is more likely to be adapted by companies since the majority of other operating systems is in the corperate world.
As Justin and goat pointed out, IE and microsoft in general has done a very poor job of optimizing code. A perfect example of this is Microsoft's frontpage. Make a page with a table on it that's pretty big. Then select the table and change the font color, not look at the html. Intead of one tag before and aft it's put code in EACH cell to have that color. The HTML is bloated when it should be intelligent enough to understand that since you've only got 1 color, that it could do the WHOLE table with just a couple tags instead of those couple x however many cells are in the table.
That's just the simple bloating, it goes WAY deeper when you look at the script IE wants compared to the TRUE standards. Microsoft has made it's own standards which aren't compatible and developers have had to accept it
.
I'm telling you all right now that Microsoft is sweating bullets since the internet is so important right now. They're starting to integrate features like the "spyware remover", and are talking about unbundling IE from the OS. What do you think all that means? Honestly I can only think of evil reasons why Microsoft is unbundling IE from the OS... maybe so they can profit from selling IE to the users that don't already know about Firefox and the alternatives?!?! I really don't know, I'm just guessing here but it seems like a logical buisness reason if you're about to start loosing a war, why not take some money and run.