The atmosphere was very relaxed and comfortable. The interns had a great degree of flexibility, which was nice to figure things out on your own and develop your skills. The people were nice and everyone got along well.
What I wish was different
The organization could have been better, but overall this is a minor issue.
Advice
Learn signal processing. It is integral to the work you will do as a developer there. Specifically, GTK+-3.0 and gtkmm widget libraries, which use C and C++.