FOSDEM offers open source developers a place to meet, share ideas and collaborate. Renowned for being highly developer-oriented, the event brings together some 5000+ geeks from all over the world. The fifteenth edition will take place on Saturday 31 January and Sunday 1 February 2015 at the usual location: ULB Campus Solbosch in Brussels. We now invite proposals for main track presentations and developer rooms. Previous editions have featured tracks centered around security, operating system development, community building, and many other topics. Presentations are expected to be 50 minutes long and should cater to a varied technical audience. The conference covers travel expenses and arranges accommodation for accepted main track speakers. Developer rooms are assigned to self-organising groups to work together on open source projects, to discuss topics relevant to a broader subset of the community, etc. Content may be scheduled in any format, subject to approval. Popular formats include presentation tracks, hacking sessions and panel discussions. Proposals involving collaboration across project or domain boundaries are strongly encouraged. Proposals for main track presentations should be submitted using Pentabarf: https://penta.fosdem.org/submission/ Developer room proposals should be emailed to <devrooms@fosdem.org> and be as detailed as possible. In particular, coordinators should indicate their affinity with the topic being proposed and provide a rough idea of the content they plan to schedule. Key dates: 15 September - deadline for developer room proposals 1 October - deadline for main track proposals - accepted developer rooms announced -- Philip Paeps Senior Reality Engineer Ministry of Information