The Raspberry PI guys have built a distro, based on Debian, for desktops / laptops.
https://www.raspberrypi.org/blog/pixel-pc-mac/
Seems they put a heavy emphasis on supporting old low powered, by todays standards, desktops and laptops.
Still in development so only runs as Live CD / USB drive, no installer. But they do have a switch for persistence so you can run it and save changes from boot to boot.
I fired it up virtualized using Debian 7 as the base target, worked great.