How many people use APL currently? Is it easy to find APL programmers?

I know of a company (Simcorp) that uses APL extensively. It is probably pretty rare that they hire someone who is already a proficient APL programmer, and most of their hires probably don't know it at all. So they train them. It's not that hard to learn. Also, most of the APL programmers are experts in some other domain, usually finance, so they don't have too many preconceptions of what programming is like.

KDB, a database built on a descendant of APL called K (which can be worked with through K and a slightly friendlier APL-like language called Q), is extremely popular in financial institutions.

I did say "in the day", APL isn't so popular today, but it's successor languages get lots of use.

Is J [0] one of those that gets lots of use? I have tried it a few times, and was impressed by its power [1] and compactness, but its rather cryptic syntax [2] put me off from going deeper into it. Might still try it more some day.

[0] http://jsoftware.com/

[1] It has some superb demos (which come with the basic install) of many kinds of apps, including up to the level of things like OpenGL graphics ones.

[2] Its succinctness [3] may be a virtue, though, once you get used to it, since programs in it are much smaller than in other languages (I'm guessing both due to its APL heritage and due to using a lot of symbols instead of words - based on what little I have read about it).

[3] That reminds me of PG's essay, Succinctness is Power:

http://www.paulgraham.com/power.html

I use k4 daily. It is is great for someone who do does not touchtype.