Can't edit the parent comment anymore, so I'll append my other thoughts here. I remembered that the "automounting" already exists in some forms, and I really l

Can't edit the parent comment anymore, so I'll append my other thoughts here. I remembered that the "automounting" already exists in some forms, and I really like these instances. When you click on an archive in a good file manager, it opens a "folder" view with the archive contents. The difference between an archive and a folder is arbitrary. It shouldn't exist and only complicates things for everybody. I assume that many applications today hand-code the logic for "if the user drags and drops a folder, we need to zip it before sending". Or they don't, and the user has to zip manually :) One could say that storing program data as "transparent" folders instead of "opaque" binary files is too much detail for the user. And users can accidentally damage something (e.g. delete one of the files inside) more easily. But I have a few counter-points: 1. Many applications already use folders, but they're doing fine. 2. File managers already open many filetypes in an editor by default (e.g. plain text, office docs), but these files are doing fine. 3. A good file manager should recognize most file types and do the more reasonable and safe thing. If JPEG is reimplemented as a folder, clicking on a JPEG should still open the image viewer instead of the folder view. That's already the case with Mac OS app bundles (the example from the original post). 4. Actually, now that folders have a "data" field, it can be used for storing arbitrary metadata. This is extremely powerful and can be used for HIDING extra details from casual users! E.g. there could be a standartized metadata header that hints to the file manager that it should treat the folder as an "opaque" file and not show the user the contents. Now, old applications that already used folders for their internal state, can mark these folders as "opaque" and prevent casual users from messing with the contents! While still allowing to see, move and delete the folder as a whole (unlike hidden folders). And while providing uniform FS access to applications and advanced users. Man, I really like this idea of arbitrary metadata for folders... It's not as necessary for files, because in practice you can just put the "metadata header" in the beginning of the main "data" (as many file formats do).