The way MacOS handles Applications is indeed humanist, but there is nothing about that user interface that intrinsically relies on strict file hierarchies. Fu

The way MacOS handles Applications is indeed humanist, but there is nothing about that user interface that intrinsically relies on strict file hierarchies. Furthermore, the implementation of it isn't generalized. The substance of what I think you're getting at is record-oriented files systems, which I consider orthogonal to the matter of tagging vs strict hierarchies. With a record-oriented files system, files are no longer seen by the OS as mere byte streams, but actually have meaningful structure. It needn't be implemented carelessly like Windows with it's zip support in Explorer. It's a very compelling idea, but as I said, orthogonal to the matter of hierarchies or tagging. Say for instance you want to edit the .plist file of Blender.app. Where is Blender.app? Probably at /Applications/Blender.app but maybe it's in /Users/zrm/Applications/Blender.app To dive into that file/directory, you must first find it. How the user is meant to find it is the question that needs to be addressed. That's a simple example of course because there are only two likely locations for it (and the later is unlikely), the file/directory you're looking for has a name you remember off the top of your head, and because either of those directories probably has no more than a few hundred entries (probably a fraction of that.) In this case the user of a hierarchical system doesn't run into much trouble because the situation is virtually ideal, but even so a tagging system would have simplified the query. The further you get from ideal circumstances, the larger the gap between tag systems and hierarchical systems grows. Additional thoughts on record oriented file systems: one example is Files-11 from VMS. An interesting property of Files-11 is that it allows files and directories to have multiple parent directories, which is similar to Unix's hard links except that directories, not only files, are allowed to have multiple parents. This gives the system the same expressive power of tags (consider each full path a file can be found at to be a tag on that file.) This allows all of your books to simultaneously be in /Books/ while still allowing you to have them in other locations like /School/cs/cs101/textbook.pdf However a system capable of expressing these relationships is the easy part. The important part is giving the human users a clean user experience, allowing them to take full advantage of the power of such a system without requiring them to manually create and maintain a web of nested links.