Safari 4 has a new feature that lets you flip through previous web pages in Cover Flow mode; the same way you view album art in iTunes. Spotlight search has been integrated into the browser as well, so you can search the text within recently-viewed web pages using the system-wide search tool. A great feature includes a crash protection mechanism that keeps the browser running, even if a plug-in crashes.
The latest version of Safari had been in beta since February. A demo of the new features was shown at Apple’s Worldwide Developer Conference in San Francisco. Aside from the visual search and Cover Flow features, the focus of the Safari 4 demo was on the browser’s performance.
Apple claims Safari 4 is around 3 times faster than Firefox 3 and Internet Explorer 8. As of yet there are not any independent backings to this claim just yet, but if the data holds up, those are some enticing claims Also according to Apple’s claims, Safari 4 aces the Acid3 test, which shows how well a browser supports the latest emerging standards, with a perfect score of 100. Internet Explorer 8 currently only scores 24. Firefox 3 scores in the 70's.
The new crash protection feature in Safari was certainly added in response to the number of rich web apps. For example, if you’re running a Flash application in one of your browser tabs, and that app crashes, Safari 4 isolates that tab and handles it without taking your other open tabs down with it. The same feature happens if you’re doing something simpler such as, watching a Flash video and it crashes. Google Chrome also has a similar feature.