Friendica and Hubzilla have events (not sure about the rsvp feature): https://friendi.ca/ https://friendi.ca/ https://project.hubzilla.org/page/hubzilla/hubzi

Friendica and Hubzilla have events (not sure about the rsvp feature): https://friendi.ca/ https://friendi.ca/ https://project.hubzilla.org/page/hubzilla/hubzilla-project https://project.hubzilla.org/page/hubzilla/hubzilla-project