We can import iCal feeds online straight into events in your account. There is also a Read/Write API so you can program bots that add events; here's some Python code to scrape events from a website, for instance.
If your events are public, others can easily export them with JSON and iCal feeds. Totally open, no authentication needed.
We support events in different time zones, and let people browse in any timezone they want.
You can also tag events for easy sorting (and Tags have privacy levels too).
We even handle reoccurring events with the standard RRULE options (although the web UI to edit this needs work)
We are about event discovery and don't try to take over an events existing ticket system, sign ups, etc ... instead we direct people straight back to the original home of the event online.
Or add events you know about to pass on to your followers. (Note the various privacy level options, and you can choose different levels for different events). This way, you help others discover great events.
Then you can go to discover, and browse all the events people you follow are publishing. If you like one ... you've just discovered a new upcoming event! You can add it to your set of events to recommend to your followers.
Then you can follow other accounts, on the same server or on other servers (more on federation later). Your can allow anyone to follow you, or approve each follower.
Fosstodon is an English speaking Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.