Ben Ramsey, an organizer of the PHP Community Conference, has written up some of his thoughts about the recent rise of "community conferences" that's been happing in the PHP community (and other communities around the world).
The PHP world is exploding with community conferences. In fact, web development technologies in general are seeing a wide range of community-driven conferences springing up around the world. I think there are many reasons for the proliferation of these conferences, and in this post, I present my opinion on how this trend came to be, along with a definition of what I think constitutes a technology-focused community conference.
So you're sure wat he means by "community conference" he offers a definition that has less to do with the content of the event and more to do with the group putting it on. These community conferences are organized by the community for the community and are usually people already established. He also mentions the "unconference phenomenon" and how it seemed like a precursor to the community conferences. He points out a few other criteria that make it "community".
Several conferences are mentioned both in the post and in the comments: PHP Community Conference, True North PHP, CodeConnexx, CoderFaire and others (not mentioned) like Lone Star PHP, North East PHP, Midwest PHP and many more.