BibTeX is a program and file format designed by Oren Patashnik and Leslie Lamport in 1985 for the LaTeX document preparation system. The format is entirely character based, so it can be used by any program (although the standard character set for accents is TeX). It is field (tag) based and the BibTeX program will ignore unknown fields, so it is expandable. It is probably the most common format for bibliographies on the Internet.
isi2bibtex is a translator which allows translation of downloaded ISI Web of Knowledge literature entries. This page is the catalog entry of the "Comprehensive TeX Archive Network".
This database provides style files (bst and sty) for use with LaTeX documents using BibTeX or AMSrefs to manage the bibliography. The styles are referenced by the academic journals to which they apply.
Biblatex is a complete reimplementation of the bibliographic facilities provided by LaTeX in conjunction with BibTeX. It redesigns the way in which LaTeX interacts with BibTeX at a fairly fundamental level. With biblatex, BibTeX is only used (if it is used at all) to sort the bibliography and to generate labels. Formatting of the bibliography is entirely controlled by TeX macros (the BibTeX-based mechanism embeds some parts of formatting in the BibTeX style file. Good working knowledge in LaTeX should be sufficient to design new bibliography and citation styles; nothing related to BibTeX’s language is needed.