directory
A macro package for LaTeX and BibTeX that facilitates the construction, the maintenance and the exploitation of an address book like database. Downloads, documentation.
http://www.geuz.org/directory/

Gbib
Overview and download of this unix software for browsing and editing database in the BibTeX format. Requires Gnome and C++ standard libraries. Free under GPL.
http://gbib.seul.org/

CL-BibTeX
A BibTeX system in Common Lisp that aims is to enable the user to format bibliographic entries using Common Lisp programs. Project page, download and project status.
http://www.nongnu.org/cl-bibtex/

CTAN directory: biblio/bibtex/
All BibTeX related files on CTAN. A collection with short descriptions for each entry.
http://www.ctan.org/tex-archive/biblio/bibtex/

Bibulus
A complete rewrite of BibTeX written in pure Perl under the GPL. Bibliographic databases are stored in XML and the bibliographies can be output in many formats (at present LaTeX, HTML and plain text).
http://www.nongnu.org/bibulus/

allbib
Perl script with a Gtk interface for managing BibTex databases available under GNU GPL. Download, news and SourceForge summary page.
http://allbib.sourceforge.net/

BibTeX as XML markup
Includes a DTD that expresses the content model in BibTeX and related converters. Documentation, download and Sourceforge project page.
http://bibtexml.sourceforge.net/

JabRef
Java GUI frontend for managing BibTeX and other bibliographies. Download, revision history, screenshots and SourceForge project page.
http://jabref.sourceforge.net/

Document Database
Web-based database solution written in PHP to organise research papers and their BibTex entries. Overview, screenshots and SourceForge project page.
http://docdb.sourceforge.net/

Convert References from web of science to bibTex
Online tool to convert the saved reference records from Web of Science to BibTeX
http://iacweb.ethz.ch/staff/maeder/wos2bib.php

bib2html
Utility that converts BibTeX files to HTML. It is available as a linux RPM file or in full source.
http://www.litech.org/~wkiri/bib2html/

bib2xhtml
A program that converts BibTeX files into HTML (specifically XHTML 1.0), based on bib2html. Download of source and documentation, and examples.
http://www.spinellis.gr/sw/textproc/bib2xhtml/

Document Archive (docarc)
A web-based database for keeping track of electronic documents and BibTeX entries, including browser plugins and console frontends. Live demo, SourceForge project page, download and documentation.
http://docarc.sourceforge.net/

Pybliographer
A tool for managing bibliographic databases. It currently supports BibTeX, ISI, Medline, Ovid and Refer formats. It can be used for searching, editing, and reformatting.
http://www.pybliographer.org/

Medline (PubMed) queries with BibTeX output
Enter a PubMed (Medline) query and it will display the result of the query as a BibTeX file which can be saved.
http://dan.corlan.net/medbibtex.html

Bibutils
A set of programs that interconverts between various bibliography formats using a common XML intermediate (MODS).
http://www.scripps.edu/~cdputnam/software/bibutils/

Bibtex2HTML
A set of tools that transforms a bibtex file into an XML file and then into an HTML file. This work is based on bibtexml.
http://www.cis.udel.edu/~sprenkle/bibtex2html/

Javabib
A BibTeX parser written in Java. Source code and javadoc.
http://www-plan.cs.colorado.edu/henkel/stuff/javabib/

bib2xml
Converts BibTeX to wellformed XML. Based on Greg Ward's btparse library.
http://www-plan.cs.colorado.edu/henkel/stuff/bib2xml/

btOOL: A Programmer's Interface to BibTeX Files
A pair of libraries, one in C and one in Perl, that give programmers unhindered access to BibTeX files. It includes btparse and Text::BibTeX.
http://www.gerg.ca/software/btOOL/

KBibTeX
A BibTeX editor for KDE. GPL license.
http://www.unix-ag.uni-kl.de/~fischer/kbibtex/

Chaaban.info: BibTex Plugin
BibTeX plugin for Wordpress, the blogging software.
http://www.chaaban.info/wordpress-plugin/bibtex/

BibTeX reference generator for W3C technical reports
An online tool generating bibliographic references for W3C technical reports in BibTeX format.
http://w2.syronex.com/jmr/w3c-biblio

Bib-it
An open source (GPL) Java front end for managing references in the BibTeX format. Download, screen shots and documentation.
http://bib-it.sourceforge.net/

Bib2x
BibTeX converter that allows to define arbitrary fileformats using a very flexible template lanuage, with additional features such as filtering. (GPL)
http://www.xandi.eu/bib2x/

Ebib
A BibTeX database manager for Emacs.
http://ebib.sourceforge.net/

BibConverter
An online tool for converting citations from IEEEXplore, Engineering Village, and ISI Web of Science to the BibTeX format.
http://www.bibconverter.net/

isi.rb
Ruby script (that also can be used as a library) which converts ISI Export Format to BibTeX Format. Formerly known as isi2bibtex.rb.
http://www-lab.imr.tohoku.ac.jp/%7et-nissie/computer/software/isi/

Jurabib
Supports citations used in the humanities and by German law students. Screen shots, documentation including FAQs, forums, and mailing list.
http://jurabib.homelinux.org/

Aigaion
A web based, shared bibliography manager written in PHP and BibTeX compliant. A lot of support for structuring and annotating the literature in overlapping topics.
http://www.aigaion.nl/

BibORB
BibTeX On-Line References Browser. A web front-end to manage and share BibTeX bibliographies on a network. History, news, screenshots and download.
http://biborb.glymn.net

BibTeX++
Improvement to BibTeX written in Java. Download, CVS access and a master thesis about the tool development.
https://info.enstb.org/projets/bibtex/

Joomla Bibtex Component
Creates and maintains a bibliographical database using the BibTex specification inside Joomla.
http://extensions.joomla.org/component/option,com_mtree/task,viewlink/link_id,1766/

Synapsen
A hypertextual card index or reference management software written in Java, with special support of BibTeX. Site contains screen shots, manual, FAQ and downloads.
http://www.verzetteln.de/synapsen/

Bibwiki
An extension to Mediawiki to manage BibTeX bibliographies. Allows importing from various sources (including Amazon) and generating list of references with BibTeX styles.
http://www.plaschg.net/bibwiki/

Bibweb
Utility for automatically retrieving bibliographical information from the American Mathematical Society's MathSciNet program. Download and documentation.
http://www.math.washington.edu/~palmieri/bibweb.php