To quote the authors at Schibo's official blog, the initial goal of this project was to see how well Google Chrome's V8 JavaScript compiler performs. Instead of building a traditional dynarec (JIT compiler) as they did for 1964 for Windows which translated MIPS directly to x86, 1964js dynamically writes JavaScript to the web page by reversing MIPS code to JavaScript. This JavaScript represents blocks of rom code. Then, if using Chrome for instance, Google's V8 compiler compiles the JavaScript to native code for the authors automatically.