I was unsuccessful in finding an online calendar that allowed the general public to add and edit their own events while not allowing third parties to edit existing events. So the best I could come up with was to make a Google calendar that allows anyone to invite it to events.
To view the calendar visit https://tinyurl.com/ForkFestEvents
To add an event to the Forkfest 2018 calendar simply make the event on your own Google Calendar and then invite email@example.com to the event.
Your event will then automatically appear on the Forkfest 2018 calendar and any future edits will be sent automatically as well.
To add the Forkfest 2018 events calendar to your Google Calendar just visit https://calendar.google.com/calendar?cid=Zm9ya2Zlc3QyMDE4QGdtYWlsLmNvbQ
If you’re logged in to Google it should ask if you want to add it to your calendar.
NOTE: I am not attending Forkfest and will NOT be doing any maintenance, etc on this calendar (or even checking the email account associated with it). I just went ahead and set it up.
In fact, if anyone would like to take over the firstname.lastname@example.org address I needed to make to create this calendar (forkfest@gmail was already taken) just drop me a PM and I’ll gladly pass control over to you.