[adamkruszewski]

Great work OP! Had done something similar as my master thesis in 2005 basing on one of Hans Reiser's papers. It was more of a quick-hack having the code written in three days so not much have survived to this day, but you can see some of it in action on an adobe flash[1] video at https://adam.kruszewski.name/assets/static/mtfs-demo.htm

[1] don't judge me, mp4 in the browser wasn't main-stream back then ;)

edit: for those without flash like me -- even as a quick hack it had manual and automatic file tagging (based on file metadata) and you could query it using logical expressions. It also had pretty nasty memory leak I didn't care to find out :) Still, without a first-class, built-in support from file managers like BeOS had for its filesystem the idea is not fully realized I think.