Forth, a common script-like language usually used for embedded systems.
GNU/Linux, MS Windows.
pbForth is basically a complete Forth interpreter which replaces the standard firmware. Once it is there, you download Forth scripts to the robot, and the interpreter then interprets and runs the scripts. There are no limitations on the number of variables, and there are a number of "libraries" that are provided for functionality like interactive debugging. This is about the ultimate in simplicity for tool setup: all you have to do is download a binary, and then write code and download it. No other tools, compilers, interpreters reside on the PC. That said, there is a cross-platform TCL GUI available that simplifies downloading of scripts and interaction with the PC.