We described most of IE8's new features in previous posts about the beta and release candidates, so here is just a short reminder of some of the most interesting new additions to IE8:

• Accelerators (think addons that make things like mapping addresses or initiating a blog post easier)
• Web Slices (make information from sites available directly in your bookmarks)
• InPrivate browsing (similar to the 'incognito' mode in Chrome or the 'private browsing' feature in Safari 4)
• Built-in clickjacking prevention
• Built-in phishing prevention
• Crash recovery (similar to Chrome; when a tab crashes, it won't take down the whole browser and the content is automatically restored and reloaded)

Speed and Security

Of course, Microsoft has also stepped up its efforts to keep users secure (pdf), and IE8 also feels a lot faster than Microsoft's earlier browsers. Microsoft famously argued that its browser has been optimized to render the most popular pages on the Internet faster than any other browser, and that JavaScript performance, which is what all the other browser developers are focused on right now, is only a small part of the puzzle. To us, however, IE8 still didn't feel very fast, especially when compared to Google's Chrome.

Best New Features: Accelerators and Web Slices

In our opinion, the two features that stand out in the new version of IE8 (besides the obvious, like speed and better security) are accelerators and web slices. One web slice we especially liked was the OneRiot slice, which gives you a quick overview of the most popular videos on the Internet right now.

In its press release, though, Microsoft argues that performing simple tasks like mapping an address takes 7 steps in Firefox, but only 3 in IE8. Of course, that is only true if you don't install the Map This addon for Firefox. And that, of course, is a large part of Microsoft's problem. Thanks to the large number of Firefox addons and other tools like Greasemonkey, you can easily replicate most of the new features from IE8 in Firefox.

Verdict

Overall, IE8 is not a bad browser, and most mainstream users who are still using IE7 will feel right at home. The problem for Microsoft, however, is that a lot of users have already moved to other browsers like Firefox, Safari, Opera, and Chrome, and IE8 doesn't really offer these users anything new or innovative. Of course, IE7 is the world's most often used browser, so this upgrade, as Om Malik rightly points out, will indeed be a welcome upgrade for millions of Windows users, and might just stop a lot of them from looking for alternatives in the near term. If you are already using another browser, however, IE8 will just look like more of the same and we can't really see a compelling reason for why you would want to switch back to Microsoft's Internet Explorer.

Compatibility

Older preview releases of IE8 already featured a compatibility view, but this release candidate takes a slightly different approach. Instead of having to switch to the compatibility mode yourself after something goes wrong, IE8 will do so automatically, based on a built-in list of sites that are already known to be incompatible with IE8.

While the IE8 team proudly points out that the browser aces the ACID2 test, it should be noted that it doesn't pass the ACID3 test.

Security

Maybe the most important advancement in IE8 is its built-in clickjacking prevention. Content providers can now add a tag to their pages and explicitly disallow their content from being shown in a frame.

Microsoft has also updated the InPrivate Browsing and Filtering modes.

Speed

In terms of speed, Microsoft decided not to follow the lead of the other major browsers, which are mostly focusing their energies on building faster JavaScript rendering engines. Instead, Microsoft's browser team argues that JavaScript is only responsible for 20% of the page load time on the 25 most popular sites online. So instead of speeding up the JavaScript engine, Microsoft optimized IE8 for these 25 popular pages.

Early Verdict

In our tests of the earlier betas and this release candidate, IE8 proved itself to be a perfectly capable browser, and new features like web slices and accelerators are quite useful and work surprisingly well. For mainstream users who are still using IE7 (or even IE6), IE8 is a major upgrade, but because Firefox has a far more interesting lineup of addons and extensions than IE, most advanced users probably won't even bother to install it. IE8 is definitely an important milestone in the development of Microsoft's Internet Explorer, but a lot of the 'new' features are already available for Firefox, Chrome, and Opera.

Released under a Creative Commons 3.0 license, the document provides a comprehensive comparison of security features of the commonly used browsers; IE (version 6 and 7), Firefox (version 2 and 3), Safari, Opera, Chrome and the lesser known Android embedded browser.

Browser security has been an ongoing problem over the years and was the first subject discussed during the browser wars panel at the Add-on conference last week. Earlier this year, Robert Hansen and Jeremiah Grossman uncovered an attack known as clickjacking, which gives an attacker the ability to trick a user into clicking where the attacker wants on a site. A good overview can be found on the Computerworld site, which has a clickjacking FAQ:

"In plain English, clickjacking lets hackers and scammers hide malicious stuff under the cover of the content on a legitimate site. You know what happens when a carjacker takes a car? Well, clickjacking is like that, except that the click is the car."

Clickjacking is one of the issues covered in the security handbook which is divided into three sections:

1. Basic concepts behind Web browsers with reviews of core standards and technologies behind current browsers and their security properties
2. Standard browser security features details explicit security mechanisms and restrictions
3. Experimental and legacy security mechanisms discusses security mechanisms that have either fallen into disuse or never caught on, as well as those yet to prove their worth.

The document appears to be an ongoing project; you can find more details here.

Image Credit: Thanks Darwin Bell