I use Inferno to develop software, as a virtual OS over top of Linux or Windows. Its community doesn't see any value in writing software just to make it easy to use for newbies. It is still actively maintained, with new changes from Plan 9 development. There are even some new software tools developed in it (eg, I wrote a build tool). Maybe this qualifies?
The only ones I can think of are languages like C++ or Rust. Perhaps emacs and vi...