It's easy to embed and has a very low footprint, plus it's quite fast. Those are all important for game developers, where usually awful C-like NIH languages abo

It's easy to embed and has a very low footprint, plus it's quite fast. Those are all important for game developers, where usually awful C-like NIH languages abound. You can't carry a lot of standard library baggage with you, which is very hard on languages like Python or Ruby (Tcl fares a bit better, for historic reasons). And – speaking of historic reasons – correct me if I'm wrong, what good embeddable JavaScript interpreter would you have used five years ago? Also, compared to Ruby and JavaScript, it's a much simpler language. You have to learn a lot less and deal with fewer idiosyncrasies, which often hurts people who "just" write scripts for big systems.