WPF diagram designer with full MVVM support, and pluggable persistence model
I wote all about this over at codeproject http://www.codeproject.com/Articles/484616/MVVM-Diagram-Designer
Features are
- Toolbox with templating for items
- Templateable items
- Draggable work surface
- Zoomable work surface
- Connector indication
- Overview box
Here is a screen shot to show you what it looks like
IMPORTANT NOTE
Old code is maintained here until I have worked through grouping feature with codeproject user https://dl.dropboxusercontent.com/u/2600965/Blogposts/2012/DiagramDesignerMVVM.zip