I knew Lua from the wiki of Tcl/Tk (another good language, but Lua sintaxis and appearance is better).
I think Lua is a good candidate to drive computer physics simulations (I work in them, because I am teaching Physics at the University of Oviedo, Spain).
Julio Manuel Fernandez-Diaz
email: julio aat uniovi ddot es
A little contribution:
SimulatedNonLocalInStrings explains how to simulate non-local variables in a string (or file)
loadstring/loadfile plus direct execution or