Mac OS X Lion's Safari is Snappier and More Stable Thanks to WebKit2
Starting in Mac OS X Lion, we've learned that Apple has started utilizing WebKit2 in their Safari web browser. The advanced version of Apple's Webkit engine was first announced in April of 2010. WebKit2 is described as a new API layer for WebKit that offers both speed and security improvements:
For the end user, the result should be a faster and more stable browsing experience. If a webpage crashes or hangs, only that single tab is affected rather than the whole browser. Subjective reports from early end users have indicated that the new Safari seems to run smoother.
Google's Chrome browser introduced a similar sandboxing model when it was introduced.