The Drupal community has put on nine "DrupalCons" before (not counting joint conferences), growing from just dozens of people to now an established, international professional event at last height of nearly 4,000, at DrupalCon Chicago.
But of course it's not enough to say "the community organizes the conference", it's really small groups of specific people, carrying out many tasks, some tasks those individuals have prior experience in, but many they're doing just because they care.
