Lightweight linux distro for old PC [on hold]

I have an old PC (~10 years) with 700 MB RAM, I want to install Linux for developing a website. I tried Lubuntu and Linux Lite but both were extremly laggy handling the two displays (both 1280*1024).

What Linux distro can be used on this old PC which has high performance and no 3D Effects like Unity.

A very big thanks for every answer!