In addition to officially uncorking the latest iPhone handset and operating system, Apple also announced Safari 5 today. The new build touts improved DNS prefetching and page caching, making it 30% quicker than Safari 4 (based on SunSpider 0.9.1, a JavaScript benchmark), 3% faster than the recently launched Chrome 5, and over two times the speed of Firefox 3.6.

Safari 5 features over a dozen new HTML5 technologies, including full screen playback and closed captions for HTML5 video, HTML5 geolocation, HTML5 sectioning elements, HTML5 draggable attribute, HTML5 forms validation, HTML5 Ruby, HTML5 AJAX history, EventSource and WebSocket. Apple has also launched the Safari Developer Program to let developers create Safari Extensions, which are sandboxed and signed with a digital certificate from Apple for security.

Another key feature is Safari Reader, a function that lets users "read single and multipage articles on the Web by presenting them in a new, scrollable view without any additional content or clutter." When the browser detects an article, users can click an icon to display the post for "clear, uninterrupted reading." Safari Reader has a few tools, such as the ability to enlarge, print, or send via email.

Interestingly, the press release for Safari 5 has disappeared on PR Newswire. That said, one is available on Apple's site, it shouldn't be long before the rollout. When Safari 5 goes live, both Mac OS X and Windows users will be able to download it here.

Update: It seems to be available now, although there is a minor error on the page. We assume someone's scrambling to get it out the door.