The Mozilla Foundation is celebrating the arrival of Firefox 3 with a worldwide party -- and an attempt to set a new world record for the most downloads ever of a single software program. OK, so that's silly and extremely geekish, but what the heck? Why not kick up a fuss?

Especially because Firefox 3 is the best Web browser I've ever seen. And I've been using the Web since before there were Web browsers.

As far as I'm concerned, Firefox has been setting the standard for Web browsers since it first appeared in 2004. At the time, Microsoft's Internet Explorer ruled the Web, and it did a lousy job. But unless you were savvy enough to try alternatives such as Opera -- or were still hoping that Netscape would get its act together -- you were stuck with IE.

Firefox was a breath of fresh air. It was everything that IE wasn't. It was secure and fast, and it supported extensions to transform the browser from a mere utility to the heart of the modern-day computing experience.

For a while, though, Firefox went into a decline. Mozilla kept adding features, but at the expense of memory, stability and performance. At the same time, Microsoft had finally been forced to improve Internet Explorer. Firefox was still better, but it was no longer that much better than IE 7.

With this latest version, however, Firefox is back on track.

Resolving memory issues

For example, one of the ways that Firefox 2 annoyed people was the way it handled memory. The longer their browsers were open, and the more pages were loaded, the more memory was used. The result for some users -- especially those whose systems didn't have much memory to begin with -- was that performance would drop to a crawl.

They also lost stability. With Firefox 2.x, I was averaging a complete Firefox failure -- all browser windows either freezing or closing down -- once every two days.

What was happening was that Firefox's bad memory management habits were zapping me. For example, Firefox 2.x used different-sized chunks of memory. Then, as it constantly grabbed and released memory, its memory map began to look like a beaten-up jigsaw puzzle. Here a hole, there a troublesome spot where someone had torn off part of a piece to make it fit, and so on.

In addition, Firefox 2.0 kept full-size copies of images in memory. When you displayed a JPEG or any of the other compressed picture formats, Firefox kept the full-size uncompressed images in memory even if you weren't currently looking at them. Since a single 100k image can eat up a megabyte-plus of memory, this old way of handling images can waste memory quickly.

Mozilla's engineers seem to have fixed that -- or at least improved it -- in Version 3. Now, if you're not looking at an image, it's been saved in memory in its original compressed format. They've also worked on the memory map issue.