Under the hood, it emulates a Macintosh Quadra 900 from 1991, a computer that ran on a Motorola CPU back when Motorola was actually an industry giant.
Macintosh.js probably falls somewhere in between. Javascript itself has been used to power and build all sorts of experiments, including some that make no sense other than as bragging rights or, of course, entertainment. Slack developer Felix Rieseberg has shown off his programming chops at using Electron, the Javascript application framework that Slack itself uses to build its popular communication tool.
