The Android M Developer Preview was released just yesterday and we're all very closely examining the changes. While there's still quite a bit to dig through, it looks like Google is getting some of the source code up right away. Before anybody gets too excited, it's likely that this code dump occurred to ensure GPL compliance. However, there are quite a few projects in the changelog that wouldn't normally require updates due to licensing, so there may be quite a bit more going live on this release.

The entire changelog totals about 29,000 commits and weighs in at about 4.7 MB. It's not entirely clear where the official starting point would be, but we generated the changelog from 5.1.1_r4, which is currently the latest release available. For this reason, it's possible that there may be some differences between the preview firmware and the changelog, but it should be quite close. In fact, there are commits dated just one day before Google I/O began.

If you're curious about what Google has been up to, check out the changelog and start looking for some of the jokes, secrets, and curious details. There are always quite a few gems buried in updates of this size.

Source: Changelog