Touring the Minefield: Firefox nightlies hands-on

Google's Chrome isn't the only browser with a publicly available developer's build. Code-named Minefield, the nightly builds of Firefox offer adventurous users a taste of what's to come in Firefox 4.

Browser development can be a risky place, even for a team of savvy, crowd-sourced enthusiasts. So it's no surprise that Mozilla calls their nightly Firefox build "Minefield." What is surprising is that, in general, today's version tended to be fairly stable.

The version I spent the day with, Firefox 3.7 alpha 6, offers multiple in-development improvements. Besides being built on the next version of Firefox's rendering engine Gecko, the current nightlies will eventually become Firefox 4, expected to be released later this year.

For right now, though, the nightly builds are a rough work in progress. Broad support for HTML5 is expected in Firefox 4, and support for the HTML5 audio and video codec WebM debuted just last week in version 3.7 alpha 4. For those curious to test it out, Google has posted a way to try out any WebM-enabled browser for yourself. There's also a build for 64-bit computers, a new version that Mozilla has only recently begun working on.

The HTML5 video and audio codec WebM earned support in Firefox 3.7 alpha 4. (Credit: Screenshot by Seth Rosenblatt/CNET)

The nightlies also offer hardware acceleration. One way to tell if the Direct2D hardware acceleration API is working is to go here and try to resize the photos in your browser. If the change occurs smoothly, then according to a developer's blog, it's probably working.

Mozilla intends its next-generation plug-in architecture to debut in Firefox 4, but it hasn't appeared in the nightlies yet. Called JetPack, it was originally designed as a separate Mozilla labs add-on, but is now only available as an SDK because Mozilla changed direction with the JetPack architecture. It will basically give Firefox a Chrome and Safari-style add-on network, based on HTML, CSS, and JavaScript, and more agile than the current one.

What has made it into the nightlies, though, is the new about:add-ons. There's not much there so far, but it does represent a radical departure from the previous add-ons management window. It also marks Firefox joining the movement towards keeping browser configuration pop-up windows to a minimum, as there are new in-window sidebars for History and Bookmarks, as well. Opera and the WebKit browsers Safari and Google Chrome have been steadily moving in this direction for some time.

Other noticeable interface changes include a big orange button in the orange left corner that conceals most of the menubar options. In the current build, it's labeled "Minefield," but mock-ups for version 4 show that will change to "Firefox," most likely when the alpha builds are ready to graduate to beta status sometime in the next few months.

By the end of the year, Firefox users will see an overhaul in how they manage their add-ons and themes. (Credit: Screenshot by Seth Rosenblatt/CNET)

Folding the menubar into a single button is nothing new, showing up in Opera's refresh earlier this year most recently. Meanwhile, Chrome has done away with the menubar entirely. The debut of Google Chrome and its minimalist interface in September 2008 kicked off more than just a browser speed war; it also forced interface designers to reconsider how much of the browser needed to be visible. For Minefield users who aren't ready to abandon their menus, though, tapping the Alt key will toggle revealing the familiar format.

Minefield's interface isn't quite as minimalist as Chrome or Opera, yet. It still ships with Status bar turned on at the bottom of the browser, and it also ships with the browser titlebar intact. It does include the option to move your tabs to the top of the browser without requiring an additional extension. Speaking of extensions, most add-ons are not compatible with Minefield. For some, this is because their max version number is set lower than the current Minefield build. For others, there are serious compatibility problems that will prevent the add-on from functioning properly, or seriously decrease the stability of the browser. Add-ons such as Nightly Tester Tools and MR Tech Toolkit can force add-ons to be compatible, but you run the risk of a significantly less-stable browser.

Minefield's performance is just as subject to change as the rest of the browser. The version I tested, 3.7 alpha 6, was incompatible with the Mozilla-designed benchmark test Dromaeo and kept freezing when trying to run the full test. On the SunSpider JavaScript test, the browser scored an average of 682.6 milliseconds on a 32-bit Windows 7 Lenovo T400 laptop, running on an Intel Core 2 Duo T9400 at 2.53GHz, with 3GB of RAM. Firefox 3.6.4 release candidate 1 notched an average of 924.6 ms over three cold runs, about 25 percent slower. Currently, that would place Minefield at around twice as slow as Google Chrome's developer's build, which has been clocked around 350 ms on SunSpider. It's unclear at this point whether Minefield incorporates Mozilla's planned update to the JavaScript engine, a combination of their in-house TraceMonkey engine and parts of Chrome's V8 engine code-named JaegerMonkey.

So far in Minefield, it looks like the menubar will be folded away behind a simple button. (Credit: Screenshot by Seth Rosenblatt/CNET)

Meanwhile, it's not clear that the out-of-process plug-in protection technology code-named "Lorentz" will debut in Firefox 3.6.4. Although it has been included in the 3.6.4 beta versions, it looks like a potential security risk is holding Mozilla back. They may wind up releasing a security fix for the hole and then retest Lorentz with the fix in place. Lorentz will be included in Firefox 4, as well.

Despite the relative stability I experienced when testing Minefield, it's definitely not something for casual users to play around with because of the ever-present potential for data loss in the browser. If you are looking to expand your comfort zone, playing around with Minefield is a relatively safe way to begin experimenting with developer's previews of upcoming software advances.