Apple Events for macOS - The unofficial Apple Events app for macOS
Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform
Facebook Local - Discover places to go and events happening near you
Zoho Backstage - Plan, run, and analyze your event— all from one place
TechEvents.co - Tech and startup events aggregator
Meetup for iOS and Android - Discover groups that are all about the things you love