For those who haven't seen, socialhub.activitypub.rocks is live! https://socialhub.activitypub.rocks/
It's a forum to discuss ActivityPub implementation, hosting, community building, etc.
Chirp! is a social network. It runs on GNU social, version 2.0.1-beta0, available under the GNU Affero General Public License.
All Chirp! content and data are available under the Creative Commons Attribution 3.0 license.