Apple has now released the latest version of its Safari Web browser, and along with its updates for its other latest releases, includes new features and tools that optimize performance.

Safari 4 is available for both Macs and PCs, with new features designed to compete against other top browsers available.

Among the new features is Cover Flow, allowing users to flip through snippets of Web sites, similar to looking through album covers in iTunes. It also includes Full History Search, allowing you to search through content of Websites in your stored history.

Other tools are included, some geared towards developers to examine page information, debug JavaScript, look into offline databases, and more.

It also claims to be able to run JavaScript 4x faster than previous Safari versions.

Safari isn’t the only new software with substantial updates; QuickTime 10 now supports HTTP streaming based on h.264 and AAC, which is new to QuickTime, but one that rivals have been utilizing for some time. It’s also harnessed the ability to automatically adjust playback bit rate, and firewall streaming.

The interface itself is also revamped, with lack of on-screen controls during video playback. It also features a slick new “Q”.