Note that SPL (Simulation Programming Language) is Young Joon's own development environment for RDS. SPL adds a scripting layer to the RDS Simulator. Although it is based around simulation, the principles apply to real-world robotics as well.
There is a lot of great material on the web site, especially if you are just learning how to use RDS or if you might want to teach a class using RDS. You can download both RDS and SPL for free, which makes learning basic robotics very low cost.