When I see Lua, the only thing I ever read is "great for embedding", "fast", "lightweight" and more often than anything else: "World of Warcraft" or in short "WoW".
Why is it limited to embedding the whole thing into another application? Why not write general-purpose scripts like you do with Python or Perl?
Lua seems to be doing great in aspects like speed and memory-usage (The fastest scripting language afaik) so why is it that I never see Lua being used as a "Desktop scripting-language" to automate tasks? For example:

Renaming a bunch of files
Download some files from the web
Webscraping

Is it the lack of the standard library?
Just because it is "marketed" (in some general sense) as a special-purpose language for embedded script engines, does not mean that it is limited to that. In fact, WoW could probably just as well have chosen Python as their embedded scripting language.
Lua as a general-purpose scripting language?