Should you wish to type them on a normal keyboard:
- https://abrudz.github.io/lb/apl has a browser bookmarklet which adds an APL language bar to the top of any web page so you can type in any input box with backtick prefixes.
- https://github.com/abrudz/Kbd has a Windows Input Method Editor (IME) that adds system-wide RightAlt+letter combos.
I know people still use COBOL, but does any important software use APL nowadays?
From Wikipedia:
> APL is used for many purposes including financial and insurance applications,[82] artificial intelligence,[83][84] neural networks[85] and robotics.[86] It has been argued that APL is a calculation tool and not a programming language;[87] its symbolic nature and array capabilities have made it popular with domain experts and data scientists[88] who do not have or require the skills of a computer programmer.[citation needed]
But the latest citation is from 2018, and some of these are just tutorials or articles.
I don't think I'd enjoy writing COBOL but array programming is actually fun to do. The experience is very refreshing compared to the verbose clean-code Software Engineering orthodoxy that seems all prevailing these days. A language that doesn't change the way you think is not worth learning, and that is definably the case with APL and its successors. It is more a tool for power users that type symbols as their way to interact with a computer
I've only ever seen APL used for Advent of Code or similar.
It's probably pretty neat given how concise you can be (or perhaps terse might be a better term), but honestly it seems like the ultimate write-only language given its peculiar choice of symbology. Based on TFA it seems like you'd need to constantly hold CTRL to accomplish even the most trivial of tasks in APL so I question the viability/utility of it.
But in spite of all that it's still a cool programming curio to my mind.
There is also the J language [1], which I understand to be a GPL reimplementation of APL. Since they went with pure ASCII, you presumably have to hold down modifier keys less.
I never used either language, so can’t comment on how useful they are. But I’ve always been fascinated with APL as an idea, especially after watching this [2] person implement Game of Life as a compact one-liner in APL! (With that compact code, maybe you press modifiers less overall than when writing more traditional/verbose languages?)
There may be some niche applications and specific businesses which use APL, but I don't think there are any fields where it's commonly used. As you've noticed, the Wikipedia article is really just cherry-picking specific instances where it has been used, some of which are 30+ years old.
>> does any important software use APL nowadays?
> No.
That's not a question one is able to answer objectively in this world full of closed source software.
Large parts of SimCorp (https://en.wikipedia.org/wiki/SimCorp) Dimension, a suite of software for investment management used by a fair number of European banks and pensions funds, are written in APL. That said, Dyalog exists, and SimCorp does not play any grand role in its existence. So there must be others out there. The mere existence of APL keyboards is proof that there is a market for these things.
- https://abrudz.github.io/lb/apl has a browser bookmarklet which adds an APL language bar to the top of any web page so you can type in any input box with backtick prefixes.
- https://github.com/abrudz/Kbd has a Windows Input Method Editor (IME) that adds system-wide RightAlt+letter combos.
(There is a variant of the bookmarklet for the BQN array language's symbols at https://abrudz.github.io/lb/bqn )