Comment by mellis

There are use cases for things like Arduino (a microcontroller development board). We'd like to allow uploading to Arduino boards from an online IDE. We'd also like to allow for interaction between sensors and actuators on an Arduino board and websites (e.g. programs written in the Scratch visual programming language). Yes, we can do much of this by having the user install a local application that communicates via web sockets, but that has its own security implications and adds an additional step for the user.