bp is a freely licensed perl package for manipulating and accessing bibliographic information. It supports bibtex, refer, endnote, procite, inspec, medline and other formats for input/output/conversion. I emailed the author as the bp homepage does not seemed to have changed in two years... will post any response as a comment.
seen at freshmeat and from the site: "pybliographer is a tool for managing bibliographic databases. It currently supports BibTeX files for reading and writing, and can also read Ovid files... It can be used for searching, editing, reformatting, etc. In fact, it's a simple framework that provides easy to use python classes and functions, and therefore can be extended to any usage (generating HTML pages according to bibliographic searches, etc)."