Lua climbs in TIOBE software index
— Paul Annesley, March 2007
Lua, the lightweight language behind lighttpd's mod_magnet, has climbed from position 44 to position 25 in the TIOBE Programming Community Index. Maybe we'll see it in the top 20 soon...
Lua is also a popular language for game scripting engines, perhaps most notably being used in World of Warcraft as an embedded scripting language for the UI subsystem.
Those who get their kicks from network monitoring (such as myself) rather than online gaming may have come across Lua in Wireshark (formerly Ethereal).
I found Lua nice and easy to learn and work with while writing a CSS/Javascript bundler for lighttpd/mod_magnet.