The latest version of Apple's web browser will sport a new JavaScript engine known as 'Nitro.'
The company claims that the new engine will be able to run JavaScript code three times faster than Firefox 3 and some 30 times faster than Internet Explorer 7.
"Apple created Safari to bring innovation, speed and open standards back into web browsers, and today it takes another big step forward," said Apple senior vice president of worldwide product marketing Phil Schiller.
"Safari 4 is the fastest and most efficient browser for Mac and Windows, with great integration of HTML 5 and CSS 3 web standards that enables the next generation of interactive web applications."
The new version of Safari will sport a number of new cosmetic and navigation features such as a revamped tab browsing system and a new 'top sites' window which displays multiple previews on a single page.
The company is also bringing the iTunes 'cover flow' system over to Safari, using the feature to navigate through book marks.
Other new features will include the ability to search browsing history for titles, URLs, and page content as well as a number of debugging and editing tools for web developers.
Apple is offering both versions of the Safari 4 beta for download on its official site.
