KDED is a daemon for running lots small workspace tasks. Tasks such as monitoring display changes, notifying you if you run out of free space, power management and so on. Running each of these as it's own process has a lot of overhead and as each task is really tiny they are built as plugins all loading by one process, the kde daemon (kded).
As there are lots of plugins at once this makes debugging a real pain, there is lots of noise from various other plugins and it can be quite hard to see which plugin is at fault in the event of a crash or memory leak. Furthermore it's difficult to test without restarting kded, which can cause over issues.
To solve this I've built a tool for running one KDED module on it's own, purely for debugging purposes.
Software is available from
git://anongit.kde.org/scratch/davidedmundson/kdedtester
Usage is very similar to KCMShell, a tool for running a KCMModule at a time.