Last week, Google announced it was launching the Open Handset Alliance, a consortium of companies working together to develop the Android platform, a mobile phone operating system based on Linux.

Today, the specifications for Android become publicly available. I'm guessing there were plenty of third-party developers that were eagerly awaiting the release of the software developer kit, more commonly known as SDK.

Here's a demo video from the SDK site:

Google said on its blog today that it is now available.

So it's official. Android is off to the races.

In addition, Google said that in order to get things rolling it was announcing the Android Developer Challenge, which will provide $10 million in awards to developers who build great applications for Android.

The first phone is expected to be built by Taiwan handset manufacturer HTC and be available in the second half of next year.

Still, Google optimistically wrote today on its blog: "with so many brilliant minds striving to design engaging, innovative applications, mobile users around the world (3 billion and counting!) can expect phones equipped with dynamic and unprecedented applications very soon."