Via Sylwester Arabas (one of the organizers):
A day-long session ("devroom") on Free/Libre and Open Source Software (FLOSS) for scientists will be held during the next FOSDEM conference, Brussels, 2-3 February 2013 (http://fosdem.org/2013). We aim at having a dozen or two short talks introducing projects, advertising brand new features of established tools, discussing issues relevant to the development of software for scientific computing, and touching on the interdependence of FLOSS and open science.
You can find more info on the call for talks at http://slayoo.github.com/fosdem2013/. The deadline for sending talk proposals is December 16th 2012; please send your submissions or comments to email@example.com.