While everyone is talking about Android 4.0 code, what is worth mentioning is that Google has also released source code of Honeycomb as well.
Despite Google's repeated clarification that holding back Honeycomb code was not intended to make it close source but to stop OEMs from starting to put it on their devices. Honeycomb was a work-around to put Android on the tablets while Google works on Android 4.0.
But now Google has released the source code for honeycomb as well.
Queru writes in his post, "This release includes the full history of the Android source code tree, which naturally includes all the source code for the Honeycomb releases. However, since Honeycomb was a little incomplete, we want everyone to focus on Ice Cream Sandwich. So, we haven't created any tags that correspond to the Honeycomb releases (even though the changes are present in the history.)
Read here: http://www.muktware.com/news/2937
Swapnil Bhartiya