FOSDEM for Free and Open Source Software Developers' European Meeting is probably the most developer-oriented event for Open Source and Free Software communities.
Official Website: http://www.fosdem.org/
Added by sindoc on November 10, 2008
Call for participation  at FOSDEM 2009 has been announced. Feel free to submit your proposals for *devrooms*, *stands*, and *lightningtalks*.
2008-11-22: Deadline for devroom & stand requests .
2008-12-26: Deadline for lightningtalk requests .