pyret-lang

This paper (http://cs.brown.edu/~sk/Publications/Papers/Published/fffkf-...) linked from "Why Pyret" (http://www.pyret.org/pyret-code/) is a long answer to "why teaching languages." It may also be useful to know that Pyret exists as part of a larger project and community. We're using Pyret to develop curricula for Bootstrap (http://www.bootstrapworld.org/), which integrates computing curricula into existing middle and high school classes, like math and physics. Part of the idea is to integrate computing into these settings to reach students who may not self-select for computing. A lot of Pyret's design, like a dead simple animation framework (https://www.pyret.org/docs/latest/reactors.html#%28part._to-...) and interfacing with real spreadsheets (https://github.com/brownplt/pyret-lang/wiki/TM028-Pyret-and-...), supports these low-friction

Pyret's runtime is entirely built on JavaScript (seriously: you can load https://code.pyret.org/editor, then turn off the network, and your IDE still works), and Pyret programs compile to JavaScript. At the command-line, it builds standalone JavaScript files that run under node. It's entirely possible to write pure JavaScript libraries that interface with the language (the compiler expects AMD style and requires that you write some small wrapping code). That's how the image library (https://www.pyret.org/docs/latest/image.html) works, for instance, and how we connect to Google Sheets (https://github.com/brownplt/pyret-lang/wiki/TM028-Pyret-and-...). Industry devs should be suspicious of Pyret's performance right now, though that will improve as time goes on. We've been spending most of our effort supporting our student and teacher user

As the sibling comment mentions, Pyret was originally written in Racket. It's now self-hosted, and I'm working on rewriting the typechecker so if you want I can answer questions about that. The current development is all done on https://github.com/brownplt/pyret-lang