DCWM is a non-reparenting, floating window manager inspired by both Plan 9's Rio and the Amiga Workbench. It is one of the smallest X window managers available at ~900 lines (180 of which are comments,) as well as one of the lightest weight (it shows a size of 725k on my box,) making it suitable for incredibly old systems. Its use of a combination of mouse movements and the super key in particular makes it suitable for old laptops which are unable to simultaneously click and drag on their touchpads.
The latest tarball can be found here: tarball (signature, which can be validated against my sourcehut here)
Note: This video is one of the earliest working builds, back when I called it riverwm.