From a high level, Microsoft breaks down IE 8's wide end user feature set into three basic categories: Speed and efficiency, "reach beyond the page," and peace of mind (security, privacy, and reliability). This is sensible enough, though of course there are pertinent improvements in this release, including some impressive and important developer-oriented changes and the continuation of IE's long-standing manageability. Instead of rattling off every single new feature, however, I'll highlight the ones that I think are most important and do the most to differentiate IE 8 from its predecessor and from the competition.

Performance

No discussion of IE 8 would be complete without an examination of the browser's performance. This has become a hot topic in recent days, what with Apple, Google, and others talking up supposed exponential performance improvements in their own products. But the truth is, IE 8 performance has been an issue for a long time because, frankly, IE 8 performance was never all that good during the beta: Throughout this process, which ran a full year from March 2008 until just this week, Microsoft improved performance with each milestone, culminating in a January 2009 RC1 release (see my review) that improved things somewhat yet again.

With the understanding that I don't run benchmarks of any kind, my feeling is that IE 8 is a bit slower than Firefox, but this relates mostly to what I call "usage performance," that is, the launching of the browser, the opening of new tabs and windows, and the responsiveness of the overall UI when performing these tasks. In web site rendering, I find IE 8 to be on par with other browsers with the sites that I visit regularly. Artificial performance testing--where you load a folder full of web pages simultaneously like "The Wall Street Journal's" Walt Mossberg does--is as pointless as the very specific micro-benchmarks cited by Apple and others because that's not the way real people browse the web. Instead, I do something that I feel is simple common sense. I use the browsers.

So from a performance perspective, IE 8 is at least in the ballpark. If performance was the only criteria, I'd have to give it a slightly lower score than, say, Firefox. But performance is only one part of the overall picture, and if you consider that the performance differences between IE 8 and the competition are at best minor, this becomes less a point of discussion. In fact, I think it's far more important to focus on other features that IE 8 brings to the table. So let's just get that out of the way and move on.

Navigation

Web browsers, by nature, are all about navigation. You load a home page of some kind and go from there. As you move back and forth around the web, you need ways to find information, and ways to return to where you were before.

Duh, right?

This sounds very basic until you realize that everyone has a different way of performing these tasks. I have a custom home page that I use for the pages I need to visit every day or least most frequently, and I don't store site bookmarks locally because I move from machine to machine so frequently. My wife, meanwhile, has a carefully crafted and nested set of bookmarks that she uses for work. Some people simply use a Spartan Google-type home page and then type addresses into the browser Address Bar, using its auto-complete functionality to find what they're looking for and move on. Others actually use search, repeatedly, to find the same sites again and again. It goes on and on.

Today's browsers have to do more than supply Back, Forward, and Home buttons. They need to address the increasingly complex ways in which users expect to be able to move around the web, visit the sites they most care about, and discover new sites. IE 8 addresses these needs in a number of ways. Some of the more interesting include:

Favorites Bar and Web Slices. The Favorites Bar is a renamed and improved version of the (reviled) Links bar from previous IE versions. This time around, the Favorites Bar is enabled by default and appears as a toolbar row above the tabs bar and Command bar, and below the Address bar. The Favorites bar works like the Bookmarks toolbar in Firefox: It's essentially a secondary (but more visual) place to store Favorites and RSS feeds. But it's also the primary interface for Web Slices, which we'll discuss in just a moment.

Internet Explorer 8
The IE 8 Favorites Bar.

I've never really appreciated the way many browsers provide a Bookmarks toolbar. I mean, why bother having two places to store bookmarks? One reason, I guess, is to give more prominence to certain bookmarks, where people use the bar as a place to store items I store on my home page: Links that are accessed every single day. And sure enough, you can do this in IE 8 now: Just click the new Add to Favorites Bar button and the currently loaded page will be added to the Favorites bar as a Favorite. (Favorites Bar items are also available in the main Favorites list under a folder called Favorites Bar.)

When you subscribe to an RSS feed in IE 8, you can check an optional Add to Favorites Bar checkbox to cause that feed to appear in the bar as well. Doing so makes some sense and is more in keeping, I think, with the preferred use of the Favorites bar, which is providing a way to access info on other sites without actually navigating away from the current page: When you click on the feed's Favorites bar button, you get a drop-down list with all of the articles in the feed. From here, you can click on the article you want to navigate to that page. (You can also choose to open all items, which just displays the raw feed, not each article in its own tab as you might expect.) This is all very convenient and logical.

Internet Explorer 8
RSS feeds provide a drop-down articles list from the Favorites Bar.

Where the Favorites bar really shines, however, is with its use of another new IE 8 feature, Web Slices. Web Slices are literally slices of Web pages, and they need to be created by web site owners. These slices provide a way to peer into a specific part of a site--say, a list of headlines from a news site-or a bit of information in compact form (as with a traffic widget). As with the RSS feed list noted above, Web slices are cool because they provide an at-a-glance look at information that is important to you, and they do so without requiring you to open a new tab or otherwise navigate away from the page you're currently viewing. Also, unlike RSS feed lists, Web slices can be quite graphical.

Internet Explorer 8
Web Slices are added via a custom new green button that appears when such a feature is available.

Web slices work best with certain types of information, such as email inboxes, weather reports, traffic updates, sports scores, auction items, and the like. These are exactly the types of things that people would need to check throughout the day, but with a typical browser, that would entail manually navigating to a specific site. With Web slices, you can simply add links to these bits of info directly to the Favorites bar, so they're always available. And when you click on a Web slice, you don't navigate to a new page. Instead, a small pop-up appears with the desired info.

Internet Explorer 8
This weather display is a classic example of a good Web Slice.

The problem with Web slices is that there just aren't many good ones yet. Third party support for Web slices is notably bad, but some of the Microsoft slices--like Live Search Weather and Live Search Traffic, are quite good. But some are horrible: The "Hotmail Service" web slice actually throws up a small advertisement too. Yuck. Hopefully we'll see some nice third party slices in the near future. My understanding is that these slices are not difficult to develop.

Smart Address bar. With the browser's Address bar getting a routine workout from users, Microsoft has moved to make the version in IE 8--now referred to as the "Smart Address bar"--a bit smarter. It has done so by matching what you're typing in the Address bar against the browser History, Favorites, and RSS feeds because many people tend to use this navigational tool to go back to the same sites again and again.

A less powerful version of this functionality existed in IE 7, but that browser would only match domain names (microsoft) and not other parts of the address (ie8 in a string like www.microsoft.com/ie8). In IE 8, the entire URL is matched against what you're typing.

You can even manage which addresses appear in the pop-down list. Just click the red "X" button to the right of any auto-supplied list to remove it from future results.

Internet Explorer 8
The Smart Address bar queries your History, Favorites, and RSS feeds as you type.

Tabs improvements. While IE 7 finally added tabbed browsing support and even raised the bar a bit with Quick Tabs, IE 8 goes even further with several new tab-related improvements. A New tab page appears every time you open a new browser tab, and this time around, it's actually useful. As in really useful. You get a list of recently accessed but closed tabs so you can recover one you've closed inadvertently. There's a link for starting an InPrivate browsing session (see below). And there are links to Accelerators (also described below) that can interact with text you've copied to the system clipboard. (This provides a handy way to use Accelerators with information you may not have found on the web.)

Internet Explorer 8
The New tab page gets you up and running quickly.

You can also reopen the previous browsing session if you had previously closed all IE 8 windows. This is Microsoft's answer to Firefox's "Save and Quit" function, and while it works similarly, there are some important differences. I sort of like that Firefox makes it an explicit option, as you are presented with this choice when Firefox closes a window with multiple open tabs. On the other hand, IE 8's recovery functionality makes it possible to always recover the last session, whether you remembered to do so or not. This is an important distinction, and I feel that IE 8 will work better for most people in this regard.

IE 8 also supports tab grouping, using a nice coloring effect to group tabs that are in some way similar. Typically, you'll see this coloring effect when you're reading a page and CTRL-clicking links to open them in new tabs; all of the tabs you open from the current page will be colored with the same color. If you open other tabs separately from the current page, however, each will have its own color. These colors don't appear until you've grouped two or more tabs in this fashion. It's a nice touch.

Internet Explorer 8
Tabbed grouping adds a touch of color to IE.

Finally, IE 8 also provides a nice set of right-click tab options. If you right-click a tab, you'll see a wealth of possibilities, including Close Tab, Close this Tab Group, Close Other Tabs, Ungroup this Tab, and so on. You can also recover lost tabs from this interface, which is both handy and desirable. Certainly, Firefox offers nothing like that. (Firefox does offer tab recovery, but it's via a right-click menu average users would never find.)

Internet Explorer 8
Right-click a tab in IE 8 and you'll see a wealth of options.

Search box improvements. While I appreciate the Google Chrome functionality where the Address bar and Search box have been combined into a single entity, IE 8 continues with the more typical old-school model where these user interface elements are treated separately. (My guess is that a future IE version will combine them as well.) But the IE 8 search box is, perhaps, the best in any browser, offering the expected integration with underlying search engines and expanding on that with a cool new visual search suggestions feature. This is quite unique, and it falls under the "reach beyond the page" philosophy that applies to other features like Web slices.

With a typical browser search box, you configure a search engine once and then pretty much forget about it. When it's time for a web search, you select the search box, type in your query, tap Enter, and then view the results on the search engine's web site. This works reasonably well, and certainly it's what we've all come to expect.

Visual search suggestions turn things up a notch. With supported search engines (including Google, Live Search, Amazon.com and several others), you can actually receive visual search results right in a search box drop-down. Obviously, this makes more sense for some queries than others, and with some search providers more than others. If you are looking for a specific product, for example, you might configure the search box to use Amazon.com as the provider. As you type in the name of the product--like xbox 360--a list of Xbox 360-related products appears in the drop-down, complete with images. It's nice (and useful) effect.

Internet Explorer 8
IE 8's visual search feature provides a more pleasing search interface.

The search box also lets you switch search providers on the fly, and it includes matches from your Favorites and History in the bottom part of the search results drop-down box.

Find on page. Firefox and other browsers have long supported a nice feature I've always thought of as "inline find," where you find information on the current page not with a dialog box but rather with an inline UI control like a toolbar. IE 8 offers this functionality too, with match highlighting, and includes a nice addition: It integrates with the search box. So if you do a web search for a particular term and then land on a long or complex page that includes that text, you can then find it on the page without typing it over again. Nice.

Accelerators. Accelerators are the second major user interface enhancement in IE 8 (the first being Web slices). This feature addresses the need that arises after you've found something of interest on a web page: Often you need to copy that information and then paste it into another web site so you can perform some action, like look up an address on Yahoo! Maps, search for the term with Google, or email it to another person. Accelerators literally accelerate this process by providing a pop-up menu of choices that appears when you highlight text or a graphic in IE 8, and each of these choices is related to a web service of some kind.

Internet Explorer 8
You can easily access various web services via the new Accelerator feature in IE 8.

Unlike with Web slices, however, there are already a number of excellent third-party Accelerators available. IE 8 ships with several pre-installed, including four Microsoft entries--Blog with Windows Live, E-mail with Windows Live, Map with Live Search, and Translate with Live Search--but you can easily access to an excellent and huge collection of third party Accelerators, including those related to visual search (Amazon, Google, eBay, New York Times, and many others), mapping (Yahoo!, Live.com), people (Facebook), travel (TripAdvisor, National Geographic), weather (weather.com), and many other categories. There's a lot there.

New and improved security features

As web browsers reach rough functional and performance parity, while simultaneously providing the all-important window through which our local computing services and web-based cloud computing services meet, security--as well as related topics like privacy and reliability--is increasingly a priority. Here, IE 8 truly shines compared to the competition. I'd like to highlight some of the more impressive advances.

InPrivate Browsing. Internet Explorer 8 can optionally run in a new InPrivate Browsing mode that effectively hides your tracks as you travel around to the more nefarious parts of the web or, what the heck, secretly shop for a wife's birthday present online. More specifically, InPrivate Browsing turns off IE's ability to locally store or retain browser history, temporary Internet files, form data, cookies and usernames and passwords. It does allow you to download file and add sites to your Favorites. By default, IE add-ons like toolbars are disabled in InPrivate Browsing mode, but you can change that from Internet Settings if desired.

You can start browsing in this mode in a few different ways, but the most obvious are to choose InPrivate Browsing from IE 8's Safety menu or to select Open an InPrivate Browsing window from the new tab page. In either case, a new browser window will appear with a new dark blue-gray InPrivate badge to the left of the Address bar. To close an InPrivate session, simply close the browser window.

Internet Explorer 8
InPrivate Browsing helps you cover your tracks ... you know, when you're buying presents for your wife.

A related feature, InPrivate Filtering, is a first step in addressing the way in which many web sites share data with each other. Consider a mainstream web site like wsj.com, for "The Wall Street Journal." This site is certainly reputable, but it utilizes advertising services that work across multiple non-WSJ web sites. Once these services have collected information about you on wsj.com, they can track you across other sites that utilize the same services. This is usually innocuous, but it's possible that a malicious site could take advantage of this capability and deliver dangerous content via other sites.

InPrivate Filtering provides basic protection against this potential kind of attack by preventing, by default, over 10 cross-site calls. It's not enabled by default, however, but once you enable it you have decent control over how it works. For example, you could lower the threshold for cross-site content (down to a minimum of 3), choose to allow or block specific sites, and so on. It's interesting to look at just to see what the sites you visit are up to. You might be surprised.

SmartScreen Filter. IE 8's SmartScreen Filter is the new version of the anti-phishing filter that debuted in IE 7. It's been renamed to reflect the fact that it now performs both anti-phishing and anti-malware functions, protecting you and your PC from electronic attacks. So if you attempt to browse to site that is known to deliver malware, or attempt to download a known-bad file, IE 8 will prompt you with a warning.

Internet Explorer 8
Redrum, redrum. Here, you see two different SmartScreen protections: A malicious site (the red background) and a malicious download (the dialog box).

You can manually check the current web site if you're unsure of something. When you do so, the SmartScreen Filter tells you what it knows about the site. You can also report a web site that you think might be fraudulent. Microsoft says that almost 50 percent of the data in its SmartScreen database comes from users.

Compatibility View updates. Microsoft knew early on that changing the default IE 8 rendering engine to be standards compliant would break a large number of web sites, so they built a prominent Compatibility View button right into the Address bar. This button lets you trigger an IE 7-like rendering mode if the current web site isn't displaying correctly. The Compatibility View button pretty much works as advertised, but it puts the onus of compatibility on the user. So late in IE 8's development, Microsoft came up with a more elegant solution.

It's called Compatibility View updates, and it's an opt-in IE 8 feature that lets the browser continually maintain a list of web sites that need to be rendered with IE 8's legacy renderer. When you hit such a site, IE 8 silently slips into its IE 7 renderer. And when those sites are eventually made to be IE 8 compliant, IE 8 will again silently switch over to its default renderer.

This is a great change, and it largely alleviates the pain that would have otherwise been associated with upgrading. And of course the Compatibility View button is still there if you need it. In practice, I've seen IE 8's compatibility improve dramatically over the past several months and while there are still some glitches from time-to-time, it appears that this feature will indeed help the company and its customers make the transition in a largely painless fashion.

Tab isolation. One of Firefox's most heralded features is its ability to recover from a crash and restart the browser with all of your previously open tabs in place. That is indeed a great feature, but most of the time the browser crashes, it's because one of those tabs has navigated to a page where an add-on or Flash-like browser extension has triggered some error.

Microsoft's solution to this issue is pure elegance. Why even crash the browser at all? If an errant add-on or web site is causing the crash, IE 8's new tab isolation functionality ensures that only that single tab crashes, and then recovers, all while not affecting the rest of the browser's tabs at all. And when a tab does crash and then recover, you'll see a balloon help window explaining what happened.

Crash recovery. That said, browsers do crash. So IE 8 expands on IE 7's crash recovery functionality by not just reloading crashed tabs and pages but by also restoring them, complete with any form data you may have entered before the crash.

Address bar domain name highlighting. It seems like a small thing, but IE 8 also highlights (bolds) the domain name in the URL, helping you to ensure you're visiting a legitimate web site. Consider the following complex (but imaginary) URLs to see why this is important:

http://engineer.bold.microsoftsite.com?a=10987345;b=09078232
http://microsoft.engineer.bold.hackersite.com?a=10987345;b=09078232

If you weren't paying attention--and who is, really?--you might not notice that the second address points to a malicious web site. But when you highlight the domain name like so, the difference is a bit more apparent. It's like the third brake light on automobiles:

http://engineer.bold.microsoftsite.com?a=10987345;b=09078232
http://microsoft.engineer.bold.hackersite.com?a=10987345;b=09078232

But wait, there's more

There's so much more going on in IE 8, of course, but I have to draw the line somewhere. For developers IE 8 provides much better web standards support than previous versions and ships with its standards rendering mode enabled by default. (IE 8 still lags behind the competition with web standards, however.) Web developers who need IE 8 to render in its legacy rendering mode can force the browser to do so with a simple bit of HTML code. (They can, in fact, choose from three rendering engines on a page-by-page basis: IE 5.5 Quirks Mode, IE 7, or IE 8 Standards Mode.) IE 8 also ships with a full suite of integrated developer tools, including an excellent Developer Toolbar. (Previous versions of these tools were separate downloads.)

For businesses, IE 8 continues IE's tradition of providing excellent deployment tools and options, OS slipstreaming, and Group Policy support. This is a facet of the browser's functionality that the competition, curiously, has never seized on. And it's a huge reason for its continued success.

Next: Internet Explorer 8 Review, Part 4: Conclusions