A collegue of Mats Gustafsson mentioned about Blipkit today. Seems worth checking up.
The thought struck me for a second that it could be even more interesting to integrate, than DR-PROLOG, since it is biomedically oriented. Maybe not, but worth thinking of I guess.
EDIT: Checked up with Egon, who pointed out that it doesn't seem to have a good interface for integration to Java, which would complicate things. Seems like a good point.