DE means Desktop Environment, it's the graphical interface. LXDE uses openbox as the window manager. It's the lightest WM I ever tried, but I didn't try them all. Ubuntu is a derivative of Debian. Debian is a tad snappier than Ubuntu. Combined with the light LXDE desktop, it could be a nice alternative.
It's the lightest for me too, next to puppy, but that's too "Mickey Mouse" for my liking. My one machine LXLE is running on is ancient, early 2000's, it's that old, and LXLE is running pretty slick on it.
Thanks guys, but my brain is about to explode! -- I'm going to restore my WinXP backup image and stop delving into the Linux abyss.
