Lua seems to be an amazing embedded scripting language, so why aren't more people using it? I suspect the reasons are more social rather than technological.

I am wondering to myself why the Lua programming language is not more popular as a scripting language. It has an excellent and stable implementation, great performance, and great documentation. Sure, it has some popularity within game development circles, but not many people are using it outside of those circles.

A recent announcement of the latest release of the Webkit's JavaScript interpreter, code-named SquirrelFish, has declared that they are moving to a bytecode interpreter implementation, similar in style to Lua. I am trying to figure out why they aren't using Lua. Perhaps they are suffering from the not invented here syndrome? Perhaps the needs of JavaScript are so different that they are better off,