Google has officially open sourced its Android code base and is encouraging developers to try out the new platform.

"Today is a big day for Android, the Open Handset Alliance, and the open source community," said Google software engineer Dave Bort.

"All of the work that we've poured into the mobile platform is now officially available, for free, as the Android Open Source Project."

The announcement has been made a day before the release of the first Android phone, the G1 from T-Mobile.

The source code is being issued under an Apache licence, which means it is free to use but developers do not have to make the source code of new products available to all.

Motorola is already reportedly developing an Android phone and Kyocera has also said it is planning to use the platform, but Google is not focusing on the mobile sphere alone.

"Even if you're not planning to ship a mobile device any time soon, Android has a lot to offer," explained Bort.

"Interested in working on a speech-recognition library? Looking to do some research on virtual machines? Need an out-of-the-box embedded Linux solution? All of these pieces are available right now as part of the Android Open Source Project, along with graphics libraries, media codecs and some of the best development tools I've ever worked with."

The 2.1GB code package is now available for download and developers will need 6GB to use the stack. Ubuntu is the recommended coding environment, but Mac software can also be used.