Trying out Firefox 4

It should come as no big surprise that a large part of what we do here at LWN involves web browsing. We are, after all, a web publication, and many of our sources and other information come from various places across the web, so we tend to spend a lot of time using a web browser. When Mozilla announced the availability of the first beta of Firefox 4 on July 6, it seemed like a perfect opportunity to take the new browser for a spin.

One of the biggest—most visible—changes is the overall browser user interface. For Linux and Mac users, though, those UI changes have not yet been made, though some of the new functionality can be seen. By using the "Tabs on top" selection in the View -> Toolbars menu, something of limited preview of the new Firefox look can supposedly be achieved. Based on the descriptions from Windows users, though, there is much more to the changes than just moving the tabs. Full-screen mode in Firefox 4 (FF4) may give a better preview to what the default look will be: tabs all the way at the top that hide themselves when they aren't needed.

In any case, the UI is only one part of the changes that come with FF4. Another important addition, at least for some folks, is the ability to play HD-quality video in the browser using Google's new WebM format. In my testing of the beta, videos seemed to work reasonably well—at least as well as they do using Flash in Firefox 3.5—but only at 360p. It may have been a bandwidth problem at this end, but 720p videos played poorly, if at all. It should be noted that the Flash version of the YouTube videos also suffered from some playback problems at 480p in FF4, but didn't seem to in Firefox 3.5.10.

On the other hand, in nearly a full day's worth of web surfing, FF4 was quite solid, unlike 3.5 which seems plagued by some kind of hang that happens more-or-less daily. I've always suspected Flash as the culprit, but never narrowed it down to that for sure. One of the more interesting new features in FF4 is crash protection. The crash protection feature is meant to disable a misbehaving plugin after it becomes unresponsive for 45 seconds by default. As far as I could tell, that never occurred on any of the pages visited with FF4. In the end, though, there were no crashes or hangs in five or more hours of pretty continuous use, which makes for a pretty stable beta in my book.

Another nice addition to the UI (one that Linux users do get to see in the beta) is turning the "Addons Manager" into a full-fledged tab, rather than a small pop-up window. It makes for much easier interaction when installing, updating, and configuring addons and plugins. One wonders if Preferences will eventually go that route, as the relatively small tabbed window that is used currently has gotten pretty cluttered. A reworking along the lines of the new Addons Manager would be welcome.

Installing the beta was completely straightforward: download a tar file, untar it, and type ./firefox. It picked up the settings, bookmarks, and so on from my current yum-installed version and, crucially, didn't rewrite those files in such a way that the older version could no longer read them. It is a well-behaved guest and, based on its performance so far, could easily become my default going forward. Undoubtedly, typing that will doom me to some horrible, unrecoverable crash right in the middle of pushing out this week's edition—luckily I have the laptop as a fall-back position.

There are lots of little things that will come in handy. Changes have been made to stop the CSS browser history leak by altering how getComputedStyle() works in JavaScript. That will be a boon for anyone concerned about privacy in their browsing history. There is a new "Heads Up Display" that will be useful to web developers. It looks very similar to the console provided by the ever-useful Firebug addon. And so on.

Mozilla is making a big push to get feedback on FF4. By default, the Feedback addon is installed, which puts a prominent button in the upper right. The two main choices ("Firefox Made Me Happy/Sad Because...") take you to a page to quickly fill out information about what worked or didn't. One can also include the URL of a misbehaving web site into the report. It is a quick, nearly painless way to report problems (or give kudos) on the beta.

One of the things that the Mozilla folks concentrated on with FF4 was performance. Firefox has, somewhat deservedly, gotten the reputation of being slow, and that is something that the development team is working very hard to change. There are numerous improvements in FF4 to speed up the browser, but I didn't find them to be particularly noticeable. While I use the browser constantly, it may well be that I don't push it as hard as others, or perhaps am more forgiving. In any case, FF4 certainly didn't seem slower than its predecessors; maybe over time the performance increase will become more evident.

Other than certain addons not (yet, presumably) being available for FF4, I could pretty easily make the switch, which is a little surprising to me. Other reports have found FF4 to be much less stable than I did. In any case, it seems that Mozilla is on the right track with a fairly large incremental update to its browser. FF4 is scheduled to be released late this year and it looks to be a great browser to head into 2011 with.