Google made its long—awaited debut into the tablet wars on Wednesday, unveiling the Nexus 7 to compete with Apple's dominant iPad as well as the recently announced Microsoft Surface.

The Nexus 7, developed in conjunction with Asus, features a 7—inch (17.8—centimetre) screen, making it smaller but more portable and lighter than its main competitors, which both feature screens of about 10 inches (25 centimetres). That places it in direct competition with Amazon's Kindle Fire tablet, which is by far the most successful running on Google's Android operating system.

The Nexus 7 goes on sale for $199 effective immediately on Google's online store Google Play, with delivery starting in the U.S., Britain, Canada and Australia in mid—July, Google said. That makes it far more affordable than Apple's cheapest iPad, the older model iPad 2, which sells for $399.

The Nexus 7 weighs just 340 grams, features an Nvidia Tegra quad core processor and a battery allowing for up to nine hours of video play on its 1280x800 pixel screen, or 300 hours of standby. It ships with Google's popular Chrome browser as the default programme for surfing the web. It also features Google Now, a refinement of Google's search service that provides personal information gleaned from your Google history, rather than mere internet links.

Android upgraded

Google unveiled the device at its developers conference in San Francisco, where the company gave details of its latest version of Android, nicknamed Jelly Bean, which improves major components such as touch, search, notifications and Google Maps.

Also revealed at the conference was the Google Q, a home entertainment hub that streams movies, music and other content, designed to compete with Apple TV and other entertainment hubs.

Google said some 1 million Android devices are newly activated around the world every day, with 400 million Android devices now in use.

In another mark of the rocketing popularity of Google's mobile operating system, Google said that its online store now boasts more than 600,000 apps, with 1.5 billion apps downloaded by users every day.

Google glasses

Google co—founder Sergey Brin announced that the company's network—enabled computerized eyeglasses would be made available for pre—order to the 5,000 developers attending Google's I/O developer conference in San Francisco. The price: 1,500 dollars.

Mr. Brin showcased the glasses in one of the most unusual tech demos ever held. It involved teams of skydivers, cyclists and rapellers combining to bring Brin a set of the high tech specs, while using the devices to beam live video of the event over Google Hangouts, the company's social networking video conferencing tool.

The glasses, which are actually wearable mini—computers in the shape of eyeglasses, use a tiny projector fixed just above the user's eye—level to beam information directly into the user's field of vision. The futuristic device can be controlled via voice commands or tiny buttons embedded in the frame.