At my very first professional EE position, in 1978, there was an older staff member, PhD, kind of a professor type, who was programming in APL. Naturally curious, I asked him about it and what the strange symbols on the keyboard meant. His explanation mostly flew right over my head but I asked a few questions, thanked him, and went away. In 43 years, he's the only person I ever saw using it.

Related. Others?

The APL Source Code (2012) - https://news.ycombinator.com/item?id=34064480 - Dec 2022 (58 comments)