Lua
Used by 14 peoplelua.org ↗

“It's wonderfully customizable thanks to the Lua configuration scripts, and one realizes how silly (e.g.”
Justine Haupt Interview, Science associate · via Uses This 
“My claim to fame is as the leading architect of the Lua scripting language, work I have been doing since its inception in 1993.”
Roberto Ierusalimschy Interview, Associate professor, lead architect (Lua) · via Uses This 
“I would save a Lua file, which is the scripting language that we've been primarily using since Psychonauts, and pressing Ctrl-C, Ctrl-S, would run the Lua compile, send it across the network to the Xbox dev kit, and send a command to hot-reload all the objects associated with the script.”
Kee Chi Interview, Gameplay programmer (Double Fine) · via Uses This 
“Lately I've been enjoying Lua too, mostly for its stellar embedding API.”
Micah Elizabeth Scott Interview, Hardware and software hacker · via Uses This 