Here’s what’s coming in the next version of Firefox. There’s been a lot of buzz about it lately, and it’s looking pretty good.

• Better download manager
  • You can now filter completed downloads with a search box
  • Anti-virus integration
  • Better resume support
• One-click bookmarking via stars
• Better security
• Supposedly patched memory leaks
• Better “Save Password” dialog
  • Displays password-saving buttons in a thin bar at the top of the screen after login information is sent to a server (Awesome!)
• Support for animated PNG images
  • This is awesome, because it was pretty much the last reason why everyone still wants to keep GIFs around

This beta release was scheduled for July, but was delayed due to performance regressions.  The big focus during beta release cycles is on quality assurance and bug fixing. As a former Google Software Quality Assurance Engineering Intern,  I can say that’s a big job and they’re probably sifting through tons of bugs right now.

Firefox 3 uses Gecko 1.9, a new version of Firefox’s HTML rendering engine. It passes the Acid 2 CSS test, which is a test case developed by the Web Standards Project. It now has support for full-page zoom.

It has a new “Places” feature, which is a cohesive storage framework leveraging SQLite rather than flat files, and unifies bookmark and history storage, much like on Safari. I noticed this on my iPhone: History is actually a special folder in Bookmarks.

Users can also do bookmark tagging, and the starring process makes it much easier to bookmark a page. In the URL auto-complete dropdown, stars are shown next to bookmarked pages. Pretty cool!

The other benefit of using an SQLite-powered bookmark system is that it supports elaborate search queries, allowing you to create “smart bookmarks.” Here’s an example:

place:folder=2&folder=287&queryType=1&sort=8&minVisits=1&maxResults=10

There are also lots of improvements for developers under the hood, like a new scripting API for bookmark and history queries. There are also new JavaScript features:

• Support generator expressions
• Iterators
• Expression closures
• getElementsByClassName

According to Mozilla, over 300 individual memory leaks have been plugged, and new architectural features, like the XPCOM cycle collector, have been added to reduce memory waste.

Beta 1 is not intended for mainstream users, although it is more reliable than alpha releases. There are still issues that need to be resolved before a public release. It’s useful for web developers to experiment with the new features now, and ensure that their existing sites are compatible with Firefox 3. It’s also good for experienced users, and people who want to participate in testing and bug tracking.

You can create an alternate Firefox profile, or backup your Firefox settings directory, before testing Firefox 3. Some users report that Firefox 3 deleted their bookmarks. You’ll want to avoid damaging your configuration data by making a backup. Users who want to test multiple versions of Firefox will need to use the -no-remote parameter.

Ars Technica says that “Firefox 3 is shaping up to be an outstanding web browser that delivers innovative new technologies while retaining Firefox’s signature ease of use.”