Some thoughts: The compare log from a tool like KDiff or WinMerge posted as a text file may be enough to show differences between content files. That is the sort of thing I would look at if downloading the files to see what was different. For the code itself, maybe the check-in log from a source code version control system, if one is being used. Post that as a text file in the same download folder as the distribution files. I recognize this doesn't provide the higher level context and leaves room for interpretation about what the differences mean to an end user but I think it would be a good starting point.