Shellcheck is indeed great. I needed to make a BASH script to give to my girlfriend that would install on her OS X a snake game I made. Using shellcheck made that a lot easier. For example, I didn't know that the [[ ]] syntax wasn't POSIX compliant. Really great for learning and remembering little things like that for portability.
If I'm doing any scripting, I always use BASH. However, I'm trying to actively push myself to learn another more portable scripting language. I still haven't been able to decide which out of Python, Perl and Ruby that I really want to throw myself into -- although recently I have started to become more and more attracted to Ruby.
Cool. First time I've read about real-time operating systems. A pseudo filesystem that resides in RAM is very interesting. I like how they've strived for "greater scalability from the very tiny platform to the moderate platform".