[bryanlarsen]

lua compiled to asm.js is 64% of the speed of lua native

https://kripken.github.io/lua.vm.js/lua.vm.js.html

[pygy_]

... which is about 10 times slower than the LuaJIT compiler used by OpenResty.

[Touche]

So that might be good enough in the browser but on the server where an optimized Lua engine exists, why?

[daurnimator]

That's not compiling lua to asm.js; it's running the lua vm in asm.js.

A straight up transpilation is other projects like lua.js. But you loose really nice core lua features like coroutines...