RE: https://functional.cafe/@raganwald/116046631281629022

APL is wild. Very much enjoying experimenting with J these days myself, which is an open source APL descendant, brought into existence by Ken Iverson, and Roger Hui.

Runs on Android -- an old tablet has been restored in my house, and is now an offline J machine. It runs the labs, so, endless challenges and fun.

Also Linux-kernel-OSes well supported, and it has the Playground and Juno with its amazing visualisation thingie, and every day I seem to discover another new lab which looks amazing.

The documentation and interactivity are just wonderful, and I'm definitely only scratching the surface.

Highly recommended checking out the J Wiki! There's a lot of documentation, so be prepared to give it a few goes.

Gems like Kenneth E. Iverson's "Notation as a Tool of Thought" are in there, waiting to be discovered https://www.jsoftware.com/papers/tot.htm