Now, Linux is probably more important, there are hundreds of millions of Linux-powered Web sites and business servers. And, Apache is the Web server behind almost all those Linux Web sites. But, for sheer number of end-users, I don't think you can beat Firefox. And, this success has lead to improvements in all Web browser software.
If you think about it, this really shows the power of open-source software. The U.S. Federal Courts couldn't stop Microsoft, even after they found Microsoft guilty of running a monopoly, which had been used to crush Netscape. After what amounted to a slap on the wrist, Microsoft continued on its way and Netscape continued its death spiral.
But, because the code lived on in Firefox, open-source developers were able to improve on it. Even before Firefox 1.0 was released in July 2004, power users were already moving to it. Today, over 22% of all users have moved to Firefox, according to Net Application's Market Share.
When you consider that every last Firefox user has chosen to seek out and download the Web browser that's impressive. Most PC users will use whatever is on their PC, usually Internet Explorer. That's why the European Union forcing Microsoft to give users a Web browser choice in Windows 7 is so important.
Now, as in the 80s and 90s, Microsoft continues to use any means, fair or foul, to make sure end-users have no software choices. In the last twelve months, for example, we've seen Microsoft use cut-rate XP and other methods to try to force Linux out of netbooks. Despite their efforts, though, Firefox has shown that high-quality software can gain market-share anyway.
Perhaps the most ironic thing about Firefox hitting this remarkable benchmark of a billion downloads is that it's very success though has helped Microsoft and Windows users. People switched, and still switch, to Firefox because it's better than Internet Explorer. Because of that, Microsoft has finally been forced to improve its own products.
Internet Explorer 8 is worlds better than its predecessors. While Firefox 3.5 is still better than Internet Explorer, users who will never even hear of it, benefit from Firefox. Without Firefox, and its enduring success, Internet Explorer would have continued to be a mediocre Web browser. So, even if you don't use Firefox, you owe it a debt of thanks. Thanks to Firefox, all Web browsers are better.