but the real problem with the application/zip hack is not the format,
it's that it's a very lame way of adding compression to MIME.
Very cogent argument. Perhaps you meant to say that using the content-type
to indicate compression format hides the actual content.
These days, anti-virus scanners seem to have a feature for 'scan ZIP
files too', so, even though it's lame, the auxiliary mechanisms seem
to be making their way through the infrastructure.
And Java ships with Zip-file 'file system' support.
Even though application/zip is lame, other mechanisms might be
worse. Maybe we should look harder at providing what would be
necessary to make 'application/zip' actually work, e.g., some
top-level indication of what's actually in the package?