Apple releases Safari 5 for Mac and Windows

Apple's Safari 5 opens the browser to developer extensions

Apple has updated its Safari browser with new features including a speed boost, multiple search options and new Reader software that supports HTML 5 extensions.

The company said that the updated Nitro JavaScript engine in Safari 5 had a 30 per cent speed improvement over Safari 4, giving it a three per cent advantage over Google's Chrome and making it twice as fast as Firefox, according to Apple.

DNS pre-fetching and caching of previously viewed pages also boosts the browser's speed, but will increase data throughput.

All flavours of the browser now support extensions using the Safari Developer Program. Extensions in HTML5, CSS3, and JavaScript are now supported, and HTML5 extensions including geo-location, sectioning elements, draggable attribute, forms validation, Ruby, Ajax History, EventSource and WebSocket can be integrated.

Users will also now have a choice of Google, Bing or Yahoo as the default search engine.

There was scant mention of the browser in Apple chief executive Steve Jobs's opening keynote at WWDC, and the slightly muddled launch was unusual for Apple.

The press release appeared on PR newswires, but was pulled and then reinstated with a working link to the software.

"Safari continues to lead the pack in performance, innovation and standards support," said Phil Schiller, Apple's senior vice president of worldwide product marketing, in a statement.

"Safari now runs on over 200 million devices worldwide, and its open source WebKit engine runs on over 500 million devices."