Hello Katherine: 

I read the message that niivsrb@tut.by sent to the "greenstone-users", about if is there any GreenStone plugin for djvu files, and I have the same problem. I am building a collection that is mainly PDF files and djvu files, and I would like to obtain the plugin for the djvu files. Thank you for your help about how to use the UnknownPlug and sorry for my English.

While waiting for your answer... 

Ania 

Happy New Year for all.