The Shale Sandbox houses experimental code that has not yet been accepted into the framework.
This area of the repository is open to any Apache committer who is interested in collaborating on Shale-related projects. To request access, post to the developers list and tell us what you want to work on.
Mailing list subscription info can be found here.
Even more experiments and examples can be found at our unofficial companion project: Shale Goodies.