When creating a new project:
Add additional Silverlight Widgets, by referencing all from the Silverlight Toolkit As described here
The Toolkit is installed here:
C:\Program Files (x86)\Microsoft SDKs\Silverlight\v5.0\Toolkit\Apr10\Bin \\this accordeon is broken C:\Program Files (x86)\Microsoft SDKs\Silverlight\v4.0\Toolkit\Apr10\Bin
<fc #FF0000>IMPORTANT:</fc> add the dlls to BOTH structures, as show on the img to use the widgets.
Glossar:
Has useful properties:
IsSelected - boolean - activates the Tab visibility - visible/collapsed - not opacity. Is whether visible, or not.