I spent last year ruminating on this (Independently. However I find it interesting the article was published around the same time that I was voicing my ideas to

I spent last year ruminating on this (Independently. However I find it interesting the article was published around the same time that I was voicing my ideas to a friend on this!) and toying with a few prototypes. This year I committed myself to hacking on a proper implementation (named 'libkoios' and 'koios') of it, using the Extended Filesystem Attributes. What I found interesting is that while there was a lot of prior work systems existing for tagging, none of them use the extended attributes system, which to me feels like a waste. However there are problems with ext(2,3,4)'s implementation of file tags that make it difficult to store a lot of data without compression (I'm storing one bit per tag, which allows fast masking and comparison operations per file), so I guess that is understandable. I believe that for image-based systems there is 8ch's /hydrus/ (probably the only good thing to come out of the chan-networks). One upshot of there being existing network sharing systems for tags is that it should be possible to scrape them when autotagging things (Nobody. NOBODY, wants to manually tag hundreds of photo memes, which is the main forseeable problem with file tagging).