elm-community
Some *-extra packages that are fairly popular have come to live in elm-community over time. These existing packages are managed by the maintainer listed on those repos, but no new packages are added under the elm-community name.
See maintainer_tips.md for rough guidelines on how to evolve *-extra packages.
If you are curious about the archived repos under the elm-community name, check out history.md for some notes on how they got there.