Zachtronics has added the ability to make custom "door games" to add to the in-game BBS in Last Call BBS. They're written in JavaScript. The documentation for how this work is here

one quarter of @staff! i make the website look good and/or bad depending on your personal taste
Zachtronics has added the ability to make custom "door games" to add to the in-game BBS in Last Call BBS. They're written in JavaScript. The documentation for how this work is here