[shriramkmurthi]

We started out as a Racket `#lang`. That is in principle always an option. However: the in-browser support is non-negotiable. We have many users in schools, which have very locked-down machines. Many of them cannot install new software. This is a real obstacle for many curricula, and our ability to run just off the browser has been a huge prerequisite for adoption of Bootstrap's [http://www.bootstrapworld.org/] curricula.