I'm looking for a word that is basically like crowdfunding/crowdfunded, except it's not about funding specifically and instead can mean any activity that involves a large group. Example: how would you describe Wikipedia? Crowd... written? Crowdproject? Obviously those aren't real words, those are just examples of what I'm looking for.
You have a sentence like this:
Kickstarter is a crowdfunding platform.
and I need something like this:
Wikipedia is a (adjective that implies it is written/contributed to by a large group of people) website.