I do intend to expand nav's feature set to come close to an `ls` replacement, at least for the most common workflows, whereas midnight-commander and other similar tools are perhaps closer to being (or are) file managers. I'm also hopeful that by using the completely awesome Charm [0] libraries that I can make for a pleasing/modern UI. Either way, I had a blast building nav and look forward to continuing on.
Thanks again for the comment!
But this one's aim seems to be a bit specific and not simply to be a filesystem browser (file manager) but specifically to try to be an "interactive ls". IE somehow feel like ls. Though I don't know why. It doesn't seem more useful than a normal file manager. I think it's just down to a very fine point of aesthetics, which is fair enough.
There is a simple introduction in /usr/lib/mc/extfs.d/README, or https://github.com/MidnightCommander/mc/blob/master/src/vfs/... .