I use J daily on my desktop as a calculator, and for more involved calculations. I am a senior project manager/technical designer/business developer at an engineering firm in the their Entertainment department. We do rock concerts, Broadway, film, live events, theme parks, stage machinery, art installation engineering and more. J is like my quicker-than-Excel-tryout-space. I have developed more mathematically-heavy applications in it, but when the need is for something beyond J's strengths of array handling and beautiful succinctness, I reach for Lisp for developing more of what people call apps, but they are for my sole use. Particularly SBCL. I also use Emacs Lisp a lot, since I am in Emacs all day for org-mode, writing, coding and LaTex. I am addicted to Emacs. It is the Lisp Machine for me until another is developed, or I can afford a relic.

I picked up Shen [1] a few years back to keep me from straying to far into Haskell/Idris, and I am working through The Book of Shen 3rd Edition. I had looked into Wasp Lisp years ago for fun, but I am now looking more into it since Chris Double ported Shen (and with it Klambda) over to the Wasp Lisp [2]. It made me leave any studies I started of Erlang or LFE, since my focus is on networking and distributed computing as a hobby. I always stay up to date with Racket, and use it for procedural geometry generation using Rosetta [3] instead of Rhino and Grasshopper. I actually used it to generate procedural truss for a sphere and then exported the centerlines to run analysis on the structure in RISA 3D [4].

I like to fiddle with Extempore for livecoding, but I am a mere dilettante [5]

  [1]  http://shenlanguage.org/
  [2]  https://github.com/doublec/shen-wasp
  [3]  http://web.ist.utl.pt/antonio.menezes.leitao/Rosetta/tutorials/introduction.html
  [4]  https://risa.com/p_risa3d.html
  [5]  https://github.com/digego/extempore