Apple said it was revving up the software running its coveted gadgets, training its sights on China.

Apple used its Worldwide Developers Conference (WWDC) to show off upgrades to the software running iPhones, iPads, and iPod Touch devices.

These included its own Siri-infused mapping technology and features tailored for Chinese users.

The hundreds of improvements in the iOS 6 mobile operating system due out before the end of the year come as Apple seeks to outdistance rivals powered by Google's Android software.

Apple chief executive Tim Cook kicked off the California company's annual WWDC by showing off new capabilities built into software for its hot-selling devices and slimmer, more powerful MacBook laptop computers.

Apple booted Google Maps from iOS 6, opening up another front in the war with the maker of the Android operating system. Apple's new operating system for the iPhone and iPad includes "an entire new mapping solution from the ground up, and it is beautiful," Apple's Scott Forstall told the standing-room only crowd in San Francisco.

"We are doing all the cartography ourselves. We are covering the world," he said. Apple has "ingested hundreds of millions of business listings around the world," he added, and has integrated with the consumer review service Yelp for reviews and ratings.

Although Maps does little to generate revenues directly, it often links to searches for products and services such as restaurants or businesses. Analysts say the Apple maps programme could over time move iPhone and iPad users away from Google search and reduce revenues for the search giant.

"Make no mistake, with maps and some expanded Siri features, Apple is now in the search business," they said.

Google last week beefed up its maps programme, which had been pre-installed on Apple devices.

Apple said that iOS 6 will also include a better-educated Siri personal assistant, which performs many of the search functions of Google. Siri, which made its debut with the release of the iPhone 4S, will be extended to recent generation iPad tablet computers, according to Forstall.

Another improvement to the iOS will be to incorporate Facebook in the operating system. "We have been working very closely with Facebook to create the best Facebook experience ever on a mobile device," Forstall said.

Apple also pulled back the curtain on slimmer, more powerful Macintosh laptops. The move keeps Apple, which has been dominating the market for tablet computers like the iPad, in the game against a new line of slimmer laptops using Microsoft Windows or the Google Chrome operating system.

"Today we've updated the entire MacBook line with faster processors, graphics, memory, flash storage and USB 3 connectivity," said Philip Schiller, Apple's senior vice president of worldwide marketing.

The MacBook Air is as thin as 0.68 inches (1.7 centimetres) and weighs as little as 2.38 pounds (1.08 kilos). Improved models will see a boost in speed and memory and cost less than previous versions.

The high-performance MacBook Pro will include the "Retina" display used on the new iPads, giving an extra high resolution screen.

"With a gorgeous Retina display, all flash architecture and a radically thin and light design, the new MacBook Pro is the most advanced Mac we have ever built," Cook said.