Google Groups - Google Groups allows you to create and participate in online forums and email-based groups with a rich experience for community conversations.

Calendify - Calendify is an event community where you can share, publish, and subscribe to event calendars. It helps you to stay informed about what you are interested in and what is yet to come.

DownToMeet - DownToMeet is a platform to organize, find, and attend group events.

Morse - Create, shout out, and discover nearby events in real time

Mighty Networks - Mighty Networks enables entrepreneurs, organizations, and companies to create and grow a community-powered brand.

Colloq.io - Discover a new way to the conferences you like.