The panel is a convenient container for all sorts of tools, gadgets and toys. In the K Desktop Environment panel applets are used for persistant applications which require minimal screen space during normal operation.
A scripting language would appear to be the ideal choice for creating and prototyping simple toys and novelties for this environment. Indeed, versions of KDE beyond 3.1.4 will no doubt be well supplied with KJS panel applets. However, for those developers comfortable with Python, PyKDE delivers a similar opportunity with the current set of libraries.
Panel applets are not supplied with the PyKDE components framework and are therefore described elsewhere.