and Mozilla coming out with several over the past few weeks, we thought it was time to go through just what all this activity in browser betas means for internet users. What are the differences among all the new beta browsers from Microsoft, Mozilla, Google, and Opera, and should you run one?

The term "beta" means different things to different vendors. For Microsoft, a beta isn't usually released till after a year of its announcement and testing. Before it hit beta, IE9 underwent four "" which were pretty much nothing but the underlying browser engine with a bare-bones interfaceno history, favorites, not even Back or Home buttons. Last week's beta of IE9 was our first look at the new-generation browser's proposed user interface. Opera's most recent beta is 10.7, and Desktop Team offers a nice explanation of what beta means to them:

• Thoroughly tested, though known to contain bugs

• Available for all users, but recommended only for advanced users

• Usually feature-complete

• Should never be installed over or substituted for a final release

• Data backup is highly recommended before use

Most browser-making software houses pretty much stick with this definition. Firefox and Internet Explorer show the biggest differences between the currently released version and the beta. They offer completely different interfaces from their predecessorsnotably more minimalist interfacesand different, that is much faster, performance. Google takes a different with its Chrome browser in that you have to choose from one of four channelsstable, Beta, Dev, or Canary. Each is increasingly frequently updated, and you need to run a "channel changer" app to switch among them. You can't run beta and released versions on the same computer. Google's release approach also differs from most developers' in its frequencyChrome is already at version 6 after just two years, compared with Firefox approaching just version 4 after six years of life.

Confusingly, the Chrome beta carries the same version number as the stable release. More differences can be found in the Developer release, which carries a version number currently of 7.0x, and many important new features, such as graphics hardware acceleration for Canvas graphics are still all the way in the Canary build.

Cleaner Cut Looks

One common theme among new browser betas I'm seeing is along the lines of "less is more." The new breed of browser wants to get out of the Web page's way. IE9 actually uses the least screen real estate along the top window border, which in previous versions took several rows for the title bar, navigation buttons, address bar, tabs, menus, and Favorites buttons. In IE9 Beta, you just get one line of controls for everything.

Google Chrome outdoes IE9 in one aspectit features just a single control buttonthe Gear icon, which gives access to everything formerly subsumed under the separate Page menu choice. Chrome also deprives you of a Home button, while IE9 Beta tucks this into the address bar. Opera took the interface reduction to an extreme by placing its single menu button at the very top edge of the window border, and Firefox 4 betas imitate this approach.

Another major interface overhaul started with Firefox 3's "Awesome bar"the combined address and search box at the top of the browser. This innovation, copied by Chrome and IE9 betabut not Safari and Operahas enabled a less-cluttered browser window, but there's a cost. In IE9, you lose the ability to use a search modifier such as "site:pcmag.com" to just search pages on the specified domain. And in Chrome, your typing in this box is instantly sent to Google's servers by default. IE9 at least lets you opt in to this behavior. I'm still not convinced that the One Box approach is necessarily better. I sometimes know I want to search and sometime know the address, so I like the compartmentalization. But it does make for a cleaner window.

Plug-ins and Security

In addition to the stripped-down user interface, Firefox 4 offers a new plug-in architecture that won't require restarts for updateswhich are a pain if you have lots of extensions. It also isolates the processes of plugins like Adobe Flash for added security. IE8 started the trend of isolated process groups for tabs, which Chrome took further by isolating every tab process and running the whole thing in a "sandbox" with no access to the rest of your PC, for maximum security.

Elsewhere in security, all of these browsers offer malware protection, but Microsoft has commissioned reports showing that its phishing protection is more effective than the others' and IE9 also offers cross-site scripting protection, "malvertisement" protection (where a bad ad appears on a good site), download scanning, and a privacy mode that protects from sites' snooping on other sites.

Speed, Measured Several Ways

Since its inception, Chrome has emphasized wicked fast speed, and Chrome still holds a good lead in the JavaScript speed races, as measured by the SunSpider benchmark. I tested on a 3.16GHz Core2 Duo-based machine with 4GB RAM running 64-bit . Here are the full results:

Browser Result in ms

(smaller is better) Google Chrome 7 Dev

Google Chrome 6 319

329 Opera 10.7 beta 390 Internet Explorer 9 Beta 403 Safari 5 444 Firefox 4 beta 6 560 Firefox 3.6 863 Internet Explorer 8 3989

So even though IE9 uses a second CPU core to compile JavaScript, Google's JIT (just in time) JavaScript compilation is more effective on this test at present. But JavaScript isn't everything. One of Internet Explorer 9 Beta's big pushes was for graphics hardware acceleration. Microsoft provided demos of this feature that clearly showed the payoff. Frames per second tests, with names like Psychedelic Browsing and FishIE Tank, showed that browsers with graphics hardware acceleration could vastly outperform those without on certain graphics operations. This will become significant when more demanding sites start to perform richer graphics feats, but IE9 also uses graphics hardware to speed up normal Web page compositing and display. Firefox and IE9 have the lead here, but Chrome's developer's have shown great improvements on the IE demos using graphics hardware acceleration in the Canary build. All three use DirectX 2D, available in Vista an Windows 7, and though Chrome's approach is less direct, with an intervening ANGLE layer, the Canary results look promising.

Here are my results for Microsoft's Psychedelic Browsing test:

Browser Revolutions per minute Chrome 7 beta 126 Opera 10.7 beta 183 Safari 5 864 IE9 beta 1810 Firefox 4b6 1769

The Firefox and IE9 betas' graphics hardware acceleration clearly have the upper hand here. They were also the only two that played the test's accompanying sound. Apple claims Safari includes some graphics hardware acceleration, and indeed its result is at least fourfold better than Chrome and Opera's betas, which don't. When I ran the test in Safari, however, I couldn't see the colors spinning as in IE9 Beta and Firefox 4 beta 6.

HTML5

HTML5 may sound like a clear-cut, singular specification, but every single browser that claims to be HTML5 compliant supports a different subset of its features. So it's far from being the mono monolithic checklist item that the browser makers claim. To further complicate the issues, other technologies are often lumped together under the HTML5 umbrella, including CSS3 (Cascading Style Sheets), SVG (Scalable Vector Graphics), and the Canvas scripted drawing capabilities.

HTML5 video is also far from being a solitary bullet point. The World Wide Web Consortium, which oversees Web standards, does not specify video or audio codecs, so browser makers can choose those that please them. Previously, Firefox was going with the open source Ogg Theora, while IE9 and Safart lined up on the side of the proprietary H.264. Chrome hedged its bets by supporting both.

But Google changed the HTML5 video landscape significantly with its announcement of WebM, which it would release to the world royalty free, at the 2010 Google I/O conference. Firefox, Opera, and naturally Chrome jumped on board to support the new "standard." But it's less of an issue than it may seem, since IE will be able to support WebM through a codec driver installed on the OS, and Safari can use an updated QuickTime to support it. What's more, Adobe has announced that Flash Player will support the V8 codec used by WebM, meaning any browser that can play Flash will be able to handle WebM video. This only leaves out Safari on iDevices.

An excellent measure of HTML5 support is available at HTML5Test.com. It returns a score based on a maximum of 300 points, with each point representing specific features of the standards, and bonus points are awarded for optional support, such as Google's WebM video format. I should note, however, that this benchmark simply checks for the presence of a feature, rather than whether the browser correctly executes it. The test isn't affiliated with the W3C and doesn't test for the complete set of HTML5 capabilities. All that said, it does give us some clue about how far along each browser is with HTML5 support. Here are the results for the major current and beta browser versions:

Browser HTML5Test.com

Score (out of 300) Bonus Points Google Chrome Beta 217 10 Apple Safari 5 207 7 Firefox 4 Beta 6 204 9 Opera 10.7 beta 159 7 Internet Explorer 9 Beta 96 3

Acid3 is aging and somewhat whimsical in its choice of tested-for features, but it can still show us a little. It doesn't require a table, Chrome, Safari, and Opera all get 100 out of 100, while Firefox 4 beta scores 97 and IE9, got a 95, though this is way up from IE8's 20.

Each browser maker has posted demo sites that show off what the new HTML5 and other technologies are capable of, and it's kind of fun to see which demos work in which browsers. Microsoft's Beauty of the Web site offers an "experience" gallery of 64 sites that make use of new tech. Their IETestDrive site also offers coding demos showing off specific HTML5 features, for example, Enhanced DOM Capabilities and CSS3 Media Queries. Google offers Chrome Experiments stress HTML5 and particularly Canvas support in some very clever demos. And there are more at the HTML5 Demos site. Apple has an HTML5 Showcase, but it tests whether you're using Safari, so isn't really an open standards test. Opera and Firefox also offer scattered demos on their developer pages.

Spoiled for Choice

But your choice of a browser isn't just about numbers on benchmarks and standards tests. Sure, you want speed and support. In the current crop of betas, you'll find all, though no one choice gives you everything. That said, you're spoiled for choice with what's available today compared with just a couple years ago. Chrome is largely responsible for this push for speed and new standards. And all of the software makers have contributed innovations that make up the current state of the art in browsers.

The stable Chrome 6 already boasts the fastest JavaScript speed and highest level of HTML5 support according to HTML5Test.com, but it has some catching up to do with IE9 beta in terms of graphics acceleration. That said, it will display just about any webpage without a hiccup, something you can't expect in most betas. IE9 is more stable than Firefox 4b6 in my testing, but it won't be fully baked likely for another year. Opera 10.7 beta offers a ton of extras, and Safari offers that Apple style and gleam. It's a fun time to be testing Web browsers, and I suggest you take a few out for a spin to see which fits your style best.