

Pentium II and 160MB RAM are plentiful, and it is no surprise that NetBSD is a breeze to use on it.
I got NetBSD running on a ThinkPad 760XD (Pentium MMX, 32MB RAM) which I revived around last summer, and it works just fine. Though running emacs on it is not a smooth experience with my configuration loaded, but it runs well vanilla. With enough tweaking, it can be a capable writing machine, especially with its flip-up keyboard.
The blog post is really good and insightful. I have never considered connecting aforementioned machine to the internet, but I think I might do it after reading this post just to try out Dillo.
MATE has been on most of my machines, except the BSD ones.
But past year or so, I have grown a fondness towards ctwm, and gradually migrated my machines to it, Linux and BSD alike.
It is not a DE, but the fact that I have to assemble my suite of software myself on my machines, makes the point of using DEs moot.