I was considering Crystal for Advent of Code. But when I checked it out, it seemed a lot of the shards (packages) had last commits in the "2-4 years ago" range. And one of the links in the official website's Community page (https://crystal-lang.org/community) lead to a domain squatter page (crystalshards.xyz), which raised questions of staleness.

It seems to have since been fixed to https://crystalshards.org, which does work, so I guess I just caught it in an unfortunate transitional period. I'll give Crystal a look again, thanks for the recommendation.

(Also, I didn't know about downside 1 (no Windows version) - I guess that partly explains the small community.)