Web giant Google has shown its hand, revealing plans for an all out assault on the mobile handset space using a “software stack” comprising an operating system, middleware, user interface and applications.

And troubled handset vendor Motorola is throwing its chips in with the services specialist, as one of the founding members of the Open Handset Alliance – a multinational association of technology and mobile industry leaders.

On Monday, Google ended months of speculation about its mobile plans with the culmination of a story that began four years ago.

Andy Rubin, founder of gadget maker Danger, which developed the Hiptop and later the Sidekick, went on to form another, highly secretive mobile software firm known as Android in 2003. Google snapped up Android for an undisclosed sum in 2005 and has kept quiet about the deal ever since.

But Monday’s announcement indicates that Android has spent the last couple of years in an incubator somewhere in the bowels of Google HQ, undergoing enhancements and optimisation until the time is right to be released upon the world.

That time is now and Android will be pitched to the industry via the 34 member strong Open Handset Alliance.

Aside from Google and Motorola, key founding members include, T-Mobile – the only operator to ever deploy the Hiptop/Sidekick, Taiwanese vendor HTC, US chip shop Qualcomm, and Samsung, which builds anything it thinks it can make money out of. Fifth placed handset vendor LG was also on the list.

The noticeable absentees were Nokia, which, with around 40 per cent of the smartphone market already, almost definitely won’t go anywhere near Android. And Sony Ericsson, which probably won’t. Microsoft looks to have been left out in the cold too.

The platform itself is a fully integrated mobile “software stack” that consists of an operating system, middleware, user-friendly interface and applications. Consumers should expect the first phones based on Android to be available in the second half of 2008.

Android will release a Software Development Kit (SDK) on November 12, so we don’t yet know if the platform is based on Linux like many have speculated.

The platform will be made available for free under a progressive open source licence and will be given to operators and device manufacturers. Customers will be free to customise Android “in order to bring to market innovative new products faster and at a much lower cost.

“Developers will have complete access to handset capabilities and tools that will enable them to build more compelling and user-friendly services, bringing the internet developer model to the mobile space. And consumers worldwide will have access to less expensive mobile devices that feature more compelling services, rich Internet applications and easier-to-use interfaces,” Google said.

Google chairman and CEO, Eric Schmidt, said: “Today’s announcement is more ambitious than any single ‘Google Phone’ that the press has been speculating about over the past few weeks. Our vision is that the powerful platform we’re unveiling will power thousands of different phone models.”

Rene Obermann, CEO of Deutsche Telekom, parent company of T-Mobile, said the operator will be launching Web 2.0 services based on Android for T-Mobile customers in the US and Europe in 2008.