Apple has changed the way browser history and bookmarks are displayed.
Searching your history, or even just browsing through it, is one thing. But using Cover Flow -- Apple's way of graphically navigating through files in Mac OS X -- is an inspired move. Not only can you search through the pages you've visited, but you can also view them quickly and easily in nearly full-size succession. Yes, it's cool in iTunes, but here it's really helpful. This is the most inspired use yet for Cover Flow. And, of course, it looks really, really cool in action.
In addition to sorting through history items, you can also use Cover Flow as a view option when browsing through large numbers of bookmarks. If you're someone who bookmarks a lot of sites for later reference, it's an easy way of finding a site.
Performance and standards compliance
While the user-interface tweaks are the most obvious advances in Safari 4, there are plenty of updates under the hood as well. Apple has included a new JavaScript engine dubbed "Nitro" that really makes a big difference in rendering dynamic content quickly. Likewise, Safari's implementation of WebKit -- the underlying code for the browser -- has gotten a speed boost. The results are noticeably faster rendering overall, which is a good thing because Top Sites renders up to 24 pages at one time.
Beyond general speed improvements, Safari 4 boasts wide adoption of open standards for Web development. Full support for HTML 5 offline caching offers the promise of access to Web applications (everything from games to cloud-based editing of online documents) from your computer, anytime and any place. Likewise, HTML 5 audiovisual support allows for the display of media content without forcing developers or users to deal with plug-ins to make content available.
Similarly, Safari now supports CSS 3 visual effects, animations and fonts, enabling Web developers to create customized and visually stunning sites without resorting to collections of files in larger formats. One of the best examples of this is the animated welcome to the Safari 4 page that is displayed when Safari is launched for the first time. (You can find the page online if you want to view it again later.) Another excellent example is this page. Adding to the low-footprint/high-impact feature set is scalable vector graphics (SVG) support.
From a developer's perspective, one of the best features about this media-rich set of tools is that Apple has worked hard to ensure that it complies with open standards. In fact, Safari 4 passed the Acid 3 test for standards compliance with flying colors.