"Vector Linux 5.9, released in late December of last year, is a
Slackware 12.0-based distribution that uses Xfce 4.4.2 as its
default user interface ('UI'). Generally speaking, Xfce requires
less horsepower than other UIs, like GNOME and KDE, and so Vector
Linux ('VL' for short) bills itself as an excellent operating
system to install on older, lower-powered computers. I've been
using it for the past two weeks, and like what I see.
"VL comes in several free (i.e. 'download the ISO and burn it
yourself') and non-free flavors. If you want to try VL before
installing it, there's also a live CD available..."