The history of the Unix /usr directory and merge

@khem wrote the following for our upcoming newsletter:

Ever wonder why /bin, /sbin, /usr/bin, and /usr/sbin exist? The structure is based on traditional UNIX systems; however, it has had evolution of its own. The /usr merge has been implemented in various Linux distributions. Archlinux and Fedora have switched to using usrmerge heirarchy some time ago. Rob’s post on busybox mailing list elucidates the history behind it. We are also exploring switching the Yoe Distro to use merged /usr file heirarchy for future releases.

Rob’s writeup is interesting.