It'd make more sense to me if it were compiling a very different kind of language, such as a Constraint/Logic programming language. I really like Lua for scripting, as-is.

Lua's portability & smooth C integration make it an interesting code generation target (not to mention LuaJIT's performance). And however you feel about working in Lua, its code is straightforward to generate - the syntax is refreshingly free of odd corner cases.