Don't think Pletzer has had anything to do with it since the late 90's. He sold it off years ago, in the 3.x days, to my recollection.
I am a former owner too, and the gentleman that got me the most recent version, and is assumedly the latest developer and owner is a fellow named Dan Fitzgerald. Version I have running here is 5.10h
Try emailing him at:
Daniel FitzGerald
