Google Groups - Google Groups allows you to create and participate in online forums and email-based groups with a rich experience for community conversations.
Airgora - A visual community for physical product designers
DownToMeet - DownToMeet is a platform to organize, find, and attend group events.
VSCO Messages - A place for creative conversation
Mighty Networks - Mighty Networks enables entrepreneurs, organizations, and companies to create and grow a community-powered brand.
Archive.md - archive.is allows you to create a copy of a webpage that will always be up even if the original link is down