GeeCON 2009 in Cracow was a wonderful experience, and this year Poznan held the conference. If you ever wonder whether GeeCON is worth the time and money, the answer is plain and simple: definitely yes.
I'm not able to give you a full review this time, as I'm leaving tomorrow for Paris, and I haven't prepared myself yet, but let me summarize the most important topics.
There were two different presentations about Erlang way (Actor and Agent models) of solving the problem with concurrency. One was a general overview of the problem and possible solutions running on JVM, and the other was about Akka Project/Platform that looks very interesting and above all, is simple to use (at least from what we've seen at the presentation). So far I've been trying to shield myself from concurrency problems with web servers, stateless services and optimistic locking on database level, but the solution presented here is really appealing. I'd love to try it out.
Joonas Lehtinen had a very nice lecture about Vaadin. There was a talk about Hades which is probably going to replace the solution I usually use (hibernate-generic-dao). Kuba Kurlenda is testing it on real project right now.
Stephan Herrmann was talking about an evolutionary idea for Object Oriented Programming: Object Teams. This may be the next big step we need, but it would have to gain some momentum and find a real life use in a big project. Unfortunately Object Teams do not yet have a successful example to follow. The main question I see is whether it's worth investing the time of your team, while everyone already knows about design patterns, which solve similar problems.
Spring Roo framework which is something you should know before you move to Grails or Ruby on Rails. Even if you do not plan to do it, it's a great way to create prototypes.
Waldemar Kot had a very condensed, content rich but easy to learn lecture about Complex Event Processing. It was definitely worth listening to. I'll try to infect my SQL friends with this idea, as it seems like something they would really like to do, when they move from PL/SQL to Java. Thomas Sundberg repeated his talk about Software Craftsmanship that he gave at Agile Central Europe. There was a little bit about Comet (push style Ajax), agility, OOP and lots of other interesting stuff.
And there was a great party, but that's a completely different story.
If you have a chance to go to GeeCON 2011, do not hesitate to.
PS: all the pictures come from the official GeeCON gallery. I don't know about the authors, though.