I have been playing around for a couple of minutes with yUML, an online service by Tobin Harris for creating UML diagrams using a textual input language. The diagram below is generated while you load this page. The input needed to generate the diagram is the following list of relations:
[Publication]++->*[Author], [AbstractAuthor]^[Author], [AbstractAuthor]*<->1[Person], [AbstractAuthor]*<->1[Affiliation], [Person]*->*[Publication], [Publication]^[PrintPublication], [PrintPublication]^[Article], [PrintPublication]^[InProceedings], [Publication]^[PublishedVolume], [PublishedVolume]^[Proceedings], [InProceedings]<->[Proceedings], [AbstractAuthor]^[Editor], [PublishedVolume]++->*[Editor], [Person]*->*[PublishedVolume], [PublishedVolume]^[Book], [PrintPublication]^[InCollection], [Book]<->*[InCollection] .
This diagram documents a (small) subset of the data model underlying the researchr.org application for bibliography sharing and reviewing.