Because other companies use the browser for their products.
Like AOL used to use Internet Explorer for their "AOL Explorer". to do that was NOT free, and they had to strike a deal with Microsoft. And, Of course- a company that is going to pay another company for something that will become the backbone of one of their products wants to make sure that the company is popular and stable (I'm speaking of the company, not the browser) as possible.
It's actually really ironic how IE became the "leader" in the first place. Originally it hardly counted as a program.
Microsoft made their Browser control- (you can see early revisions within their Help viewer and the "Infohelp" they used with Windows 95 programs). However, it would be up to other companies to "show off" this control.
So they made a relatively thin wrapper around the browser control- and called it Internet Explorer. It didn't come with the OS at that time, one needed to buy the Plus! pack. (In fact, at that time Netscape was a paid product as well).
Now, people didn't like IE2. because it sucked. The thing is- it sucked "by design" it was only meant as a thin wrapper around the browser control, and at the time MS already had plans to use the control themselves in various other products. People used it though- and they asked MS to add features. so they did- favourites and whatnot, and IE3 was released with much fanfare and a way better UI (for IE2, we're looking at command buttons with text labels like back, forward, home... this is OBVIOUSLY not a polished product and wasn't intended to be at the time). About this time MS decided to release IE for free. It still was not included within the OS.
Now, this was what got Netscapes attention. MS was releasing a competing product for free. And they didn't even consider it a product at first- it was their customers that told them otherwise. Anyway, this is how the first browser war started- As far as I'm concerned, the only side that even considered it a "war" was netscape. MS didn't really give a *censored*, they just did what they were doing anyway.
For example- that whole "include IE in the OS" was not a strategic move against Netscape, but they had planned it from the very beginning- it was the very PURPOSE for the HTML engine to exist. It was supposed to be, just a little system component, that got used, but never mentioned. What would have happened if MS never made IE? well, we'd all have a HTML renderer on our desktops, but half of us wouldn't even know it.
This is what happens in the business- a big company (netscape) creates a product. They sell it. they get complacent, and rest on their laurels for a few years.
Then- out of nowhere- another company creates competition. And their product is already on par with their own after one-fifth of the development time! Sometimes, the company doesn't even know it's competition- usually, it's a small outfit with a single niche product like this that the larger company wants to use. The larger company could either buy the product from the smaller company, and hope they stay in business and continue to improve the product; create their own version of the product, and hope the time in development pays off- or, simply buy the company outright. The last option works out best for everybody, since the larger company can ensure the continued development and support of the product, and the smaller company is given the stability of the larger company.
In this case the product was Internet Explorer from MS, and there was no way Netscape was going to buy MS. If anything, things would go the other way around.
People analyze the "death" of Netscape and say it was MS that choked them out of the market. The truth is, they choked themselves. Once IE was made free, not only did Netscape Not make theirs free but they basically tried to sell it on a single merit- basically, that it wasn't an MS product. However, they weren't choked out of the market by MS- they were choked out of the market because they refused to innovate- they stopped working on the product. the features they added were laughable. The only people to consider the first browser "war" as such were hardly even participating.
Anyway, that's sort of what makes me sick and pisses me off. people say "MS choked them out of the market" but MS NEVER choked ANYBODY out of the market. it's called business. if you don't innovate, you fail. period. If your main claim to fame is simply not being the other company then you can not be the other company in a dumpster somewhere, because eventually customers are going to realize that your product sucks and no amount of "but it's not IE" will convince them that they should use it.
Firefox is another story in that regard- it actually competed with Internet Explorer's features- and added some. You'll notice that it "not being IE" is not really one of the features they list- they list other features that are at least equal to, or on par with IE.
But what makes this whole thing hilarious is that the IE control was originally created as an OS component- the decision to integrate parts of it into the OS was not made later- it was the original design. And yet, somehow, them building a shell around this control and competing with another complacent company somehow got them into an anti-trust suite.
