I haven't written in APL professionally (other than fixing up existing code) but I have been responsible for an APL system and for its replacement.

I'm sure that writing a greenfield APL program is a lot of fun. Initially.

Or if you're just writing vignettes to do some temporary data wrangling then it's fine.

As a language for writing applications that do proper work and need maintaining? Wouldn't be in my top 50 choices of language. And I don't think I've worked with 50 languages yet.

Does trying to build a Youtube channel around J count as professional?

I've been livestreaming a presentation tool / time-travelling REPL for J for a few months now:

https://github.com/tangentstorm/j-prez

It hasn't paid anything directly yet, but my videos probably helped me land my current job.

At work, I use another APL-inspired language called K.

For finance or something else?

Yes, on 3 May 2020:

https://news.ycombinator.com/item?id=23055793

"Is APL Dead? Not anymore"

Believe it or not, the APL world's changed a lot since then. I still consider APL dead, but there are strong signs of rebirth.

APL dialects April[0] and KAP[1] are improving rapidly, and my own offshoot BQN[2] has gone from prototype to a full language. All of these are open source and made to work with the Unix ecosystem. While the K language isn't as close to APL, ngn/k[3] is following a similar trajectory.

This year we created a Discord/Matrix forum[4] (bridged together) for array languages, which has hundreds of members and a few conversations per day at the slowest. The Array Cast was featured prominently here when the first episode aired[5] and is also worthy of note: they say they now have thousands of subscribers.

[0] https://github.com/phantomics/april

[1] https://github.com/lokedhs/array

[2] https://mlochbaum.github.io/BQN/

[3] https://codeberg.org/ngn/k

[4] https://mlochbaum.github.io/BQN/community/forums.html

[5] https://news.ycombinator.com/item?id=27209093

Thanks for all you do! I can't wait until one of these languages reaches a 1.0 milestone.

search for aaron hsu, he made plenty of talks about APL dialects

if you like terse generic code you'll be fed for a while (too much even, Aaron's two page parser/compiler was somehow too cryptic even for my tastes :)

Ohh yeah. I've enjoyed talking with him on HN. Probably on a previous account as I never enter my email and get locked out all the time :)

That parser was mind bending.

He also wrote TFA.

q and k are still actively used in many parts of finance.

Indeed, and if you have a community of people using them, you can be very productive.

But those languages are astonishingly intimidating for new programmers -- reading from right to left, with implicit variables, different usage of brackets, types that are hard to discern, overloading of every possible bit of punctuation, etc makes it more like translating Latin than writing code.

So while a line such as : .[`:/data/raw; (); :; 1001 1002 1003]

is very succinct, the skill and concentration necessary to write that line is not something that lends itself to widespread adoption.

I've been learning APL for a bit, and have tried q too, and I disagree with the idea you need more skill and concentration to write either. Personally, for problems that suit the domain, I've found it much easier than equivalents in other languages like numpy and pandas. Q-sql in particular seems extremely convenient to have built into a language, and probably requires less concentration to write than an equivalent using manual iteration/filtering.

Yes, sorry for not mentioning that. I'm aware of kdb+ in finance (never used it personally, but wish I could).

I use J's Jd columnar database to munge data for academic research. Much, much easier than SQL. The models, I do in R because packages.

I do. But I don't really write or maintain large systems, only various tools and interfaces.