An Acronym for Bibliography style.
BST is a PostScript-like, Stack driven ProgrammingLanguage used to layout references in bibtex(1) bibliographies very few people use, despite bibtex(1)'s popularity. It has special operations for manipulating names (reducing forenames to their initials etc) and a complete ban on recursion (it gives the error message Curse on you, wizard, before you recurse on me).
One page links to BST:
lib/main.php:944: Notice: PageInfo: Cannot find action page