repl.it contains code from a few years ago. That's way before a huge amount of general optimizations in emscripten, as well as asm.js. Here is a more up to date Lua VM running in JS:
But even that is already out of date ;) just this week I found that I was building Lua with a bad choice of optimization flags. We include Lua VM benchmarks in the emscripten test suite, so for the latest numbers (with the proper optimization flags), see
http://kripken.github.io/lua.vm.js/repl.html
But even that is already out of date ;) just this week I found that I was building Lua with a bad choice of optimization flags. We include Lua VM benchmarks in the emscripten test suite, so for the latest numbers (with the proper optimization flags), see
https://docs.google.com/spreadsheet/ccc?key=0AkuGewEm05tZdFd...
It's possible to run the Lua VM in JS at only about 50% slower than a native build.
edit: fix link