OmegaLinux
OmegaLinux is an Arch-based, rolling-release Linux distribution featuring the lightweight LXDE desktop. It is suitable for installation on older computers with as little as 1 GB of memory.
VS
Besgnulinux
Besgnulinux is a lightweight, desktop Linux distribution based on Debian's "stable" branch. Using the JWM window manager, it is designed to be fast, lightweight and easy to use, suitable for older and low-specification computers.