I've been wanting to get around to learning an apl-like language like K for a while. Is there any favorite starting points for anyone who's done this?
And Ike itself is not a bad environment to play around with K https://johnearnest.github.io/ok/ike/ike.html
It has a repl as well in: https://johnearnest.github.io/ok/ you can find source here: https://github.com/JohnEarnest/ok and manual here: https://github.com/JohnEarnest/ok/blob/gh-pages/docs/Manual....
If this is the entirety of K - https://kparc.com/k.txt it does fit on a single full-screen page.
it has a well-written manual and is a great jumping off point. the source is written in ~1000 lines of js. so you can look at how each primitive is implemented.
there is a k-enthusiast element.io server[1] where you can ask any question you like. folks are friendly!
EDIT: another commenter shared most of this info. oops :-) i'll add as well ngn-k browser repl[2] which has some docs and a fuller feature-set than oK. this is probably the most-used open source k right now. the author is active in the above element server, and still patches bugs and makes updates.
[0] https://github.com/JohnEarnest/ok