(fourth RacketCon): Greg Hendershott - Emacs à la mode DrRacket 

Cool demo, especially for persons such as myself who are too lazy to read docs. I really like racket mode, it's much easier for the emacs beginner than geiser

How to install, doc, code: github.com/greghendershott/racket-mode

yes, but how can one do graphics, for example draw a circle, from emacs ? It seem like the code must be sent to a "viewer" not just a subprocess of emacs

The bit I mention stealing from Lennart Green -- who is all kinds of hilarious and awesome -- comes from this: Lennart Green Card Magic