BibGene is a BibTeX-compatible Macintosh application for maintaining databases of references to scientific papers. BibGene was designed to maintain BibTeX information in a cross-linked object-oriented format which makes it easier to detect and correct common mistakes such as multiple spellings of an author's or journal's name. BibGene also provides a way to store information that does not fit well into the BibTeX framework, such as citations from one paper to another, pointers to online preprints, and author addresses.
BibGene is available as freeware for PowerPC-based Macintosh computers.
I am not currently supporting 68K-based Macs, but an older unsupported 68K version of BibGene is available.A brief BibGene user manual is online. For examples of BibGene databases, and of BibTeX and HTML exported by BibGene, see my bibliography page. You can also see some of BibGene's features on the following screenshot (follow the link for a full-sized image):
BibGene is based on Gene, a shareware genealogy database program. For more detailed information about the user interface features shared by Gene and BibGene, or on the file format they use to store their data, see the documentation available from the Gene home page.