Refer style bibliographies are searched using a simple home made Perl script.
Translation into other formats is achieved with a wonderous array of Perl scripts, some very elegant (because they use bp, see below), and some very baroque, automatically translated from my original awk scripts by the wonderful a2p (which faithfully preserved their full baroque splendour).
(I had to move things to Perl because of a move from a Unix server to a Windows/NTT server).
The best place to go for information about conversion between different bibliographic format is Dana Jacobsen's home page. He is the author of the excellent bp bibliography package, and an excellent survey of bibliographic software.