"Lua 1.0 was developed as a data-description language for Petrobras, the Brazillian oil company. It’s hard to be any more “industrial” than that.
Highly recommended is the authors’ HOPL paper, An Evolution of Lua.
Also incidentally, one of the defining of features of Lua (all along) that hasn’t been mentioned in this thread is extensible semantics. In Lua, reading from or writing to a table can mean anything you want it to mean. So, lots of fancy features (inheritance, laziness, autocreation of subtables, functions with private state, memoizing, currying) can be implemented by the user in just a few lines, instead of having to be built into the language core."