Nemp provides an Application Programming Interface (API) that allows other programs to interact with Nemp. In Windows XP, this API was used for the Deskband - a concept that was not continued in Windows.
Keyboards with a small display that can run small apps also seem to be out of production. As long as my G15 is still working, I use the small NempG15App that comes with the installation to control the player.
The functionality of the multimedia keys that are now available on many keyboards is unaffected by this. They work completely independently. Custom apps for other display keyboards are possible, but this concept seems to be becoming rather extinct.