Roberto wrote a nice article on the design choices behind Lua. It discusses why coroutines, pcall, and other features of the language work the way they do.
http://queue.acm.org/detail.cfm?id=1983083
In this article we discuss how embeddability can impact the design of a language, and in particular how it impacted the design of Lua from day one. Lua3,4 is a scripting language with a particularly strong emphasis on embeddability. It has been embedded in a wide range of applications and is a leading language for scripting games.
