Microsoft's Windows Phone 7 has entered its Tech Preview stage.
The Tech Preview stage means that the product has passed its beta testing, but is still not regarded as finished.
The Windows 7 OS has been made available to a select group of wireless carries, smartphone manufacturers and developers, who have been given a device that meets the WP7 chassis requirements.
Tech blog Boy Genius Reports states that the company also released a document detailing the hardware requirements for the platform as well as a number of other user interface features and functions.
The Windows Phone 7 OS will require a 3.7in multi-touch screen, a 1GHz processor, a five-magapixel camera, an industry standard graphics chip and three front-facing dedicated buttons.
The blog also reports that the user interface of the upcoming OS is as minimalist in feel as the previous Windows Mobile OS.
Experts have expressed concern that the company may miss the scheduled launch date for the platform, as the Tech Preview stage normally lasts for a few months.