By "lots of big brains," I think you mean Mike Pall :). But yeah, LuaJIT is really fast.
Julia (http://julialang.org/) is another dynamic language designed from the start for high performance, although the objectives are slightly different from those of Lua. While LuaJIT is fast at everything, Julia is really optimized so that running the same code many times is fast. Running a function the first time can be much slower than in other dynamic languages, I think because there is no baseline JIT or interpreter.
Julia (http://julialang.org/) is another dynamic language designed from the start for high performance, although the objectives are slightly different from those of Lua. While LuaJIT is fast at everything, Julia is really optimized so that running the same code many times is fast. Running a function the first time can be much slower than in other dynamic languages, I think because there is no baseline JIT or interpreter.