Where do developers and authors hang out?

There’s a IRC channel called #gemini on irc.tilde.chat. The port using TLS encryption is 6697.

Ben has a Delta Chat group. Set it up and send him a message and he’ll add you.

=> Announcement with contact information (archive.org)

There's an unmoderated newsgroup with some activity:

=> comp.infosystems.gemini

There was a mailing list (gone since December 31, 2021):

=> About the mailing list