This year I went to the YAPC::EU::2009 conference in Lisbon. I missed the one from last year, so being a little less accustomed to those gatherings, I recovered the same feeling that I got at
my first YAPC conference in Birmingham in 2006 : this community is like nothing else I've seen before.
I had been to quite a lot of computer science conferences in my previous life, where the climate was very different. In the academic world, people mostly think about the papers: if your paper is accepted, you go to the conference to add one more line on your publication list; if it is not accepted, maybe you go nevertheless to see what are the ideas in fashion, and to do a bit of networking that may help you getting accepted on the following year, or build an international circle that will give more credibility to your next research proposal. In that world, it's nice to see the community again, but meanwhile there is always a feeling of competition, because the person sitting next to you might well be that anonymous expert that turned down your last paper submission. Question sessions may be quite harsh, too, because people in the audience sometimes are more interested in showing off their own knowledge, rather than genuinely trying to clarify what the speaker was talking about.
YAPC conferences are very different. People come because they love it, and some of them even come on their own time and money. They love the fun, of course, the special dresses, the jokes, the culture; but they also love to join for shaping new ideas, new tools, new constructs that will be helpful to the whole community. They don't come for marking their territory; they come for passion, and they know that by working together, everybody can help Perl to improve and expand.
I think I've never heard any aggressive question at a YAPC: rather, the audience sometimes helpfully points to some resources that the speaker might have overlooked.
All of this makes YAPC very much enjoyable, so I'll definitely try to attend next year in Pisa.