A while ago I wrote about two file managers for Windows that implemented Miller columns (see the photo below). However, one of them was being discontinued (UltraExplorer) while the other one was just to buggy to be used daily (WinBrowser).

I was just reminded over the comments that a Miller column based browser was posted as a project on Kickstarter. Currently just a couple of days from the end of the donating period and still not meeting a goal of $7500. Fingers crossed.

More info on their web site: http://bit-commander.com/