That depends on what you're using them for.
If you are a developer, then DesktopX is better hands-down. Not even close. Konfabulator is actually pretty primitive when you move away from pre-canned widgets.
Now, if you're talking as a user and just want to run widgets, that's just a matter of taste. There are more good widgets for Konfabulator IMO than DesktopX. But Konfabulator can only do widgets whereas DesktopX can do entire desktops and have animated desktop objects which I think give DesktopX an overall edge.
Also, Konfabulator widgets rae basically "take them or leave them". Whereas with DesktopX, you can import a widget into the dev environment and even end users can tweak them from a GUI.
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