Limited RAM Linuxes...Puppy or Bodhi
Sure Linux will run well on <1GB RAM...but it will run much better without KDE or Gnome Desktop Environment. Certainly a fully loaded hacker distro like Kali is perhaps not pre-configured for general purpose computing. I go Puppy Linux on my 12 year old laptop with 384MB RAM...with 20GB hard drive and certainly never leave home without bootable puppy on a stick