It changed hands/names about 3 or four times over the years, I think it was last owned(?) by Dragonware, or A&D, or McDonald & Assoc., (the UIS3 guys). Apparently there was some ill feelings somewhere and the one main file, powerdos.prg) was released to the public domain by the author iirc.
Think the package was something like Netware or OSMnet, then Powernet, then ?...
I think this is the Author...
http://www.nickm.launch.net.au/ProjectArchive/latham.html
Wish I knew how to get hold of the owner of the SW, because I was sent a special disk by mistake, and it would probably help the Atarians to be able to share it.