exec /opt/local/bin/kwin &
exec /opt/local/bin/startkde
Of course, those paths assume you installed KDE using darwinports. If you installed KDE manually or through fink, you may have to change the paths. Anyway, once those changes are in place, X11 will now start up correctly with KDE and the KDE window manager. BTW, make sure to run X11 in Full Screen mode. It would be difficult to use KDE when intermingled with Aqua. The last (and most annoying) problem to getting X11 and KDE working was that I had no functioning Alt key - the Option key simply did nothing. After much fooling around, I found the following solution:
Create a file called .Xmodmap in your home directory. Open it in some editor. Add in the following two lines:
keycode 66 = Alt_L
keycode 69 = Alt_R
Save it. If you're already running X11, type the following in:
xmodmap ~/.Xmodmap
Otherwise, just start X11. Now option will act as Alt.

