Google promised, and Google delivered: the source code to Google Android 4.0.1, codenamed "Ice Cream Sandwich," has been released to the open source community. And as a nice side bonus, the code now available encompasses the complete source code history tree, which includes the never-before-open Android Honeycomb family of releases.
I'm not a developer, so I'll defer to Google Android Open-Source Project software engineer Jean-Baptiste M. "JBQ" Queru's post to the Android Building mailing list for details:
This is actually the source code for version 4.0.1 of Android, which is the specific version that will ship on the Galaxy Nexus, the first Android 4.0 device. In the source tree, you will find a device build target named "full_maguro" that you can use to build a system image for Galaxy Nexus. Build configurations for other devices will come later.
Later in the same post, he writes:
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.)
This is a very cool thing for Google to do - I stand by my opinion that Google had been misrepresenting the openness of the Android operating system to everybody up to and including the US Senate, but this goes a long way towards realigning perception with reality.
But on the other hand, it seems pretty transparent that they only did it for fear that Google's rushed Motorola Mobility buy coupled with the closed Google Android 3.0 release tree would intensify the scrutiny on the search giant at a time when it can't afford much more of the legal spotlight.
There's no point looking a gift horse in the mouth, though, and I'm looking forward to seeing what the Android hacker community puts together with Ice Cream Sandwich as its new foundation.