GNOME is an open source desktop environment
KDE is a powerful graphical desktop environment for Unix workstations.
"The motivation is that font size 12 under kde seems to be much larger than under gnome"
from question "Is there a way to determine if GNU Emacs 23 (or higher) is running under KDE?"
"On kde aptana ran perfectly quicker than on gnome at the best of times"
from question "Why is Aptana Slow on Gnome 3 and Nvidia on Mageia 2?"