Last time I looked at numbers, IE had around 90%. That's a long way different from 99.9%!
Mozilla is completely free and entirely open source. That means that you can not only download the program, you can download te sourcecode - and, if you want to, modify it any way you like.
But this means nothing to the non-programmer, doesn't it? [b[No![/b] Read on, and I'll explain why.
But first, why is Mozilla free? Who is paying for it? No-one. The people who write it are highly skilled - you have to be highly skilled to write modern software. As such, they can and do command high salaries in their day jobs. These guys don't need money, they have got money. They work on Mozilla for kudos. Not kudos from you or me - what do they care for our opinions? What do we know about the minuitae of writing software? No, kudos from one another. That's their motivation. And here is how it works.
Imagine you are having a new house built. Your builder - call him Bob - isn't working for money (he's already wealthy enough), he's working so his mate Jim the carpenter can look at the house he built and say "Wow! Great job, Bob!" If Jim (and Fred and Louise and all the rest of them) don't say "great job", then Bob has wasted his time building you a house.
So far so good: but now we get to the really clever bit: this isn't just free software, it's open source software - i.e., as part of the deal, Bob has to not only let anyone look at the "house", he also has to provide the source code. In other words, he works away at building it, knowing all the time that his mates will not only inspect the finished product, they will read his original code, examine all his workings. If software was a house, open source software like Mozilla is a house made with glass walls, and Bob's mates will be looking at it trying to find every little mistake, every last bet nail or not-quite-right-angle joint.
And, of course, because it's software not really a house, and because programmers are an anti-social and compettive breed by nature, they will be only too pleased to fix those little mistakes and tell Bob all about it.
When it comes to quality control, there is nothing that produces the goods like open source. Mozilla has gone from dreadful (two years ago) to clunky but very stable (one year ago) to the unquestioned most stable browser on the planet (as of about 6 months ago). As a matter of routine, I have 50 or 60 windows open nearly all the time, and reboot maybe once every three or our weeks, or when I change hardware, whichever comes first.
Those of you using Netscape probably already know that there are, essentially, three different Netscape browsers.
(1) The old ones: 4.8 and below. Good in their day, but their day was a long, long time ago. THey can't cope with even the basics of modern web design, notably CSS, which almost every web page uses now.
(2) Netscape 6.x. Dreadful things! These were based on very early, pre-release versions of Mozilla, and they were big, slow, and ultra-buggy. Ugly as sin too.
(3) Netscape 7.x. Vastly improved. These were based on Mozilla 1.0x - i.e., the same as early Mozilla versions, but with stuff added. It's the added stuff that makes Netscape such a poxy browser: it's loads of advertising and commercial junk that serves no useful purpose (bar attempt to attract you to AOL's site and the sites of the various cronies they hang out with) so as to be able to extract money from you, or bombard you with extra ads, or inflict the dubious delights of REal Player on you.
Sure, recent Netscape versions are rebranded Mozilla with extra crud to make it bigger, slower and uglier, but don't judge Mozilla by Netscape 7.x - by the time AOL programmers have finished adding in the advertising stuff to Netscape 7.x, the version of Mozilla they are starting from is long since outdated and has been replaced by a better one. Honestly, I can't think of one single reason to use Netscape anymore. It is unable to do anything that Mozilla can't do better, fster, and more reliably.
The ad-blocking in Netscape 7.1, of course, is (like everything else in NS) second-hand from Moz. Mozilla has had it for ages.
Poor old IE, depite its massive (and illegally gained) market share, hasn't done anything of note by way of development for 4 years or more. Since 5.0, we have seen 5.5 (which added nothing) and 6.0 (which added more nothing). I "upgraded from 5.0 to 6.0 a little while ago, and I honestly can't think of anything that 6.0 gives me that 5.0 didn't already do. Except waiting - 6.0 is noticably slower, and it has a minor video display problen with overlapping windows which 5.0 never had.
In the meantime, all the ideas have come from the two enginerooms of browser development: Opera and Mozilla. Tabbed browsing? Opera invented it, Mozilla copied it, Microsoft still don't have it. Ad-blocking? Mozilla invented it. Skins? An Opera development. Meaningful user-security tools? Mozilla again. Pop-up control? Opera. Are you getting the picture?