What was the weirdest/worst/most obscure editor you've ever used?

I'm in the process of learning DOOM Emacs to move away from Codium, and the process prompted me to reflect on editors I've used in the past. There is one obscure editor I'm having flashbacks of: jGrasp. It was the editor I learned to code in because it's what my professor recommended. It is ugly and barebones as hell. Also, it's written in Java. I would never use an editor like it today, but I didn't know any better at the time.