...While some of the code may work with older versions of Android, some sporatic work is done to support them. Open source (Apache 2 license), copyright by Google. So you can use the code according to the terms of the license, A perpetual work-in-progress. It's updated whenever the need arises. To some extent, Grafika can be treated as a companion to the Android System-Level Graphics Architecture document. The doc explains the technology that the examples rely on, and uses some of Grafika's activities as examples. Features are added to Grafika as the need arises, often in response to developer complaints about correctness or performance problems in the platform.