Hello,
as a minor addition to Stefan's posting, I would recommend you to take the base/run/printf.run script as a starting point for experimenting with Genode on seL4. It relies on the mentioned basic mechanisms but does not depend on user-level device drivers. Another example may be hello_tutorial/run/hello.run (that showcases a simple client-server scenario) if you remove the dependency from the timer driver from the code and the run script.
Cheers Norman