It isn't just that ATS is understaffed. I gave up trying to contribute because I got tired of getting active pushback on basic style issues that I would expect CS undergrads to have figured out by the end of their first semester.

Case in point:

https://github.com/githwxi/ATS-Postiats/pull/35#issuecomment...

Seriously, "When the dust settles, we will think of better names ..."

Hongwei is a great researcher, but he hasn't displayed particularly good judgment wrt. software engineering, and no amount of external contributors can fix problems that come down to a maintainer who actively pushes bad practices. It was almost heartbreaking to walk away from ATS for me, but I came to the conclusion that I just wasn't going to be able to fix the things that needed fixing while Hongwei was making decisions like these.

At (IIRC) Hac Boston 2012, Edwin Brady gave a talk on what was at the time a very work-in-progress version of Idris. There were several points during the talk where he went to demo some basic feature in the repl, got some nasty error message, and went "oh right, I haven't implemented that yet." But even then, it felt more polished than ATS does now.