Debian - or Devuan if you don't want systemd - can be made as spartan as you want. It boots in those mentioned few seconds on my 15yo T42p (Pentium M@1.8GHz, 2G

Debian - or Devuan if you don't want systemd - can be made as spartan as you want. It boots in those mentioned few seconds on my 15yo T42p (Pentium M@1.8GHz, 2GB). Use Sid/Unstable if you want more up-to-date software with the accompanying larger flow of updates.