BibTeX

1. A style independent file format for bibliographies that expresses each entry in a similar manner to a Perl hash; eg:

   @article{Gettys90,
      author = {Jim Gettys and Phil Karlton and Scott McGregor},
      title = {The {X} Window System, Version 11},
      journal = {Software Practice and Experience},
      volume = {20},
      number = {S2},
      year = {1990},
      abstract = {A technical overview of the X11 functionality. 
      This is an update of the X10 TOG paper by Scheifler \& Gettys.}
   }
   

   - From http://www.ecst.csuchico.edu/~jacobsd/bib/formats/bibtex.html


2. A program (of the same name) for converting a BibTeX file into LaTeX or other ASCII document formats.

It was designed in 1985 by Oren Patashnik and Leslie Lamport specifically for conversion into LaTeX. The standard BibTeX utility follows this equation:

style file + list of citations from LaTeX + BibTeX "database" = LaTeX file listing the cited references

In addition to keeping all your references and citations nicely organised, the most valuable use of BibTeX is the seperation between data and style that XML is known for. By using BibTeX, an author can get a BibTeX style customised for each journal they might publish in and format their references correctly without even knowing what that is. IMHO, this would save a lot of headaches for 1st-year university students! (While ensuring that they'd be unable to publish without computer assistence, muhahahaha :)