Strange Loop

September 26-28 2018


Peabody Opera House


St. Louis, MO

Native Speed on the Web: JavaScript and asm.js

The language of the web is JavaScript, and while it has gotten much faster in recent years, it still tends to lag behind native code. However, for truly performance-sensitive code, recent developments in compiling code from languages like C++ to JavaScript, as well as in optimizing that code in web browsers, have gotten JavaScript much closer to native speed while still maintaining full backwards compatibility.

We will show how such performance is achieved using asm.js, present several demos of real-world usage, and discuss current limitations and possible future directions of that approach as well as how it compares to other proposals for improving performance on the web.

Alon Zakai


Alon is a researcher at Mozilla, working on techniques for compiling code to the web platform. In 2010 Alon founded the Emscripten open source project which utilizes LLVM to compile C and C++ to JavaScript, with the goal of allowing existing codebases to be automatically ported to standard web technologies.