Mathematica TreeView like in C#

Is it possible to have a Mathematia Tree View like in C# WIndows Forms ?
Also I feel there is needed more GUI elements in Mathematica (Matlab GUI builder is more advanced at the moment :()

Could you give an example so those of us who do not know C# can understand the question.

Also, be specific about what GUI elements you are talking about.

You could certainly build something like this with OpenerView. Here is a small (10 second) example:

OpenerView[{a, Row[{Spacer[10], Column[{b, c}]}]}]

And a more sophisticated treatment could nest multiple OpenerViews.

Thanx , What is the purpose of Row ?

Just a formatting construct to allow me to put the Spacer[10] before the Column so that the Column is indented.