It's become clear that what we actually have here is a "project", and that we ought to be able to save all the data (source XML files, NCD values, lists of modified lines, current state of processing, settings in the main screen etc.) in one big file -- a compressed archive -- and reload it. I've begun creating the infrastructure to support this (the usual Modified variable, filename tracking, SaveChanges prompting etc.). I've got the New and Save stuff all written with the exception of the actual code which saves the file; this is going to be based on a TJclCompressionArchive object, which looks simple enough from the one demo that comes with it, but I don't know if it'll work out in the end. I would have used the open-source ZipMaster component, but it's currently uncompilable in Delphi 2009. I don't see why the JCL component won't do the job, though.