Stellarium is now constructed so that new or special features can be added as plugin modules eg. At the present moment the plug ins are only supplied in source code. The general purpose plug ins now available are:
Anglemeasure :- To measure the angle between two objects on the view window
CompassMarks :- Places a relative set of degree markers on the horizon
Ocular :- Creates a window for a predetermined telescope view.
The programs ares in the form of a *.DLL file and a *.ini file, placed in a folder "modules" of the Stellarium root directory or the documents and settings/user area allocated to the config.ini file and is called by a key combination Ctrl (?) and sub key if necessary.
As these modules are only available in source code they need to be compiled.
For those Windows users who cannot compile there are compiled versions available at http://www.geocities.com/wendygblyde