<b_jonas> slashlearn euclid//Euclid is a short geeky game in which the goal is to do Euclidean compass and straightedge constructions in as few steps as possible. It runs in the browser, found at "http://www.euclidthegame.com/". It was popular among #esoteric regulars in 2016-07.

Queuestack is when you're confused about whether something should be a queue or a stack, and end up with a complete mess. See https://xkcd.com/954/ .