James Haywood covers the basics of integrating WPF inside 3ds Max 2011 using dotNet 3.5
Quoted from article:
"Some time ago I wanted to start getting my head around WPF, and especially how I could integrate tools made with WPF into Max. So I decided to start with something simple, which was to take an existing script that displays a progress bar using standard Max controls and convert it to WPF.
Updated to v0.9 - This Render Effect displays additional information such as frame number - file name - render time etc. as overlay onto your rendered image. Useful for previews - previzualisation and other non-final renderings - should work with any 3dsmax-compliant renderer. All parameters animatable.
A small tool which creates cross-section splines of one or several objects in the scene.