JabRef is a cross-platform BibTeX reference manager. I use it to manage my references for my research, not only because BibTeX is my preferred format, but also for the added features such as keeping track of my pdfs.
Michael Ley, and Patrick Reuther. Extraction et gestion des connaissances EGC'2006, Actes des sixièmes journées Extraction et Gestion des Connaissances, Lille, France, 17-20 janvier 2006, 2 Volumes, volume RNTI-E-6 of Revue des Nouvelles Technologies de l'Information, page 5-10. Cépaduès-Éditions, (2006)