For people looking for an alternative to Facebook events that isn't spammy like evite and the like, I recommend checking out https://gath.io

It requires no login, basically you provide an email address, you get a unique editing URL, you make a nice looking event form, and people can RSVP there. Your event and all related info is deleted from their DB 2 weeks after the event is over.

Gathio

An easier, quicker, and much less privacy-invading way to make and share events

@darius there is also https://wikical.com/ and https://gettogether.community/ but they all don't support #federation yet.
wikical | collaborative calendar of upcoming events

Collaborative calendar to discover and share special events. Ordered by important deadlines. Group them according to your interests. Get notified.