“Better to think of window managers? Gnome, KDE etc. In my (limited) experience KDE2 has the tastiest eye-candy, and seems to be the most easily configurable in terms of menus. AFAIK, now also GPL'd - at least licencing issues have been resolved that prevented its inclusion in Debian Linux. However I have not used Gnome extensively. Also, XFree86 support is currently being (or has been) developed for the cygwin utilities (WinNT). So for portabilities' sake this should also be taken into account in the choice of window manager/graphical toolkit used. Let's not forget Mac OS X while we are about it! (apparently OS X porting is easier than the cygwin port, going by posts on the grass developers list).” (John Reid)
It took me a lot of time to decide between KDE and Gnome, finally I choose Gnome because KDE was looking too much like windows. I have tried to develop the application only on GTK+ but it was too much trouble, with lack of nice GUI. I have also chosen Gnome because it is in C. I may be old fashioned here, but I still think C is the language as Linux is in C, so they should know better....