LUA is a very cool and useful scripting language IMHO that is very common on many other platforms and applications. It has tons of oline documentation and examples for anyone wanting to learn it.
LUA has been an integral part of MorphOS since quite some time, and here you can also use it to replace Arexx since it can use Arexx ports.
Krashan is developing a native source level debugger (LUA Explorador 0.5 was released recently). Plans are also to make it possible to create MUI interfaces and use LUA to create custom MUI classes, making it possible to Create native applications with it.