RefDB is a reference database and bibliography tool for SGML, XML, and LaTeX/BibTeX documents. It allows users to share databases over a network. It is accessible through command-line tools, through a web interface, from text editors (Emacs, Vim), and it contains a SRU server. Programmers can use Perl and PHP libraries to integrate RefDB functionality into their own projects. RefDB is released under the GNU General Public License and runs on Linux, the *BSDs, OS X, Solaris, and Windows/Cygwin.
JabRef is an open source bibliography reference manager. The native file format used by JabRef is BibTeX, the standard LaTeX bibliography format. JabRef runs on the Java VM (version 1.5 or newer), and should work equally well on Windows, Linux and Mac O
Bibster is a Java-based system which assists researchers in managing, searching, and sharing bibliographic metadata (e.g. from BibTeX files) in a peer-to-peer network.
This list provides a quick overview of the landscape of open-source bibliographic software; both where is has been, but more importantly, where it may yet go.