The SproutCore Experimental framework contains code that is not ready to be included in the core framework and is actively being worked on. This code is being improved with the expectation that eventually the code that lives in this parent framework will become a part of the core framework. If you are interested in using a framework that is experimental, can you do the following in your Buildfile:
config :your_app, :required => [:sproutcore, :'sproutcore/experimental/example']
which will include the experimental framework and whatever modifications it makes to the core framework in your project.
Experimental frameworks may not be kept up to date with the master core code, and by nature will be unstable and less tested than the core code. We will try our best to maintain experimental code and ensure that code that will not make it into the core framework is pruned, but there are no guarantees.