Hi Birgit,
I am a University of Melbourne student working on an seL4 project for my Computer Science Masters under Toby Murray.
Mind if I join the hangout? It would perhaps help a lot for me to speak to some other people who have worked with seL4.
My masters research project is one nicked from Gernot a few years back, looking into mapping an object-capability programming language onto seL4's capability system.
Cheers, Stewart