In addition to Paul Stovell's excellent list:
- No custom markup extensions.
- No
x:Type markup extension.
- No
LayoutTransform (though there are workarounds).
- No convenience metadata for
DependencyProperties (have to manually define measure/arrange/render invalidation, property changes, etc).
- No light-weight
Drawing or DrawingContext classes (have to use Shape elements).
- No commands.