It seemed that Mac OS X Lion will introduce quite a huge number of internal performance changes, and among them is Apple’s browser, Safari. To me, Safari is quite dreadful to use as it’s not the smoothest browser among few that I’ve used, and not very stable too to say the least. But now it’s getting much improvement (in Lion, that is), thanks to WebKit2.

Apple will be utilizing WebKit2 in their Safari web browser in Lion. 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

WebKit2 is a new API layer for WebKit designed from the ground up to support a split process model, where the web content (JavaScript, HTML, layout, etc) lives in a separate process from the application UI. This model is very similar to what Google Chrome offers, with the major difference being that we have built the process split model directly into the framework, allowing other clients of WebKit to use it.
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.