I love programming with .NET, especially C# 3.0, .NET 3.5 and WPF. But what I especially like is that with Mono .NET is really platform-independent.
Now I heard abou
There is a library called Silverform SDK that aims to provide cross-platform WPF and Silverlight implementation.
The library is implemented in managed code and currently works with OpenTK and Unity3D as render backends. Major functionality, such as binding, layout, main controls and primitives, has already been implemented (check Unity web player demos here). Initially it has been focused on Unity3d render, while support for standalone Mono applications will be added as a separate build in the future.
Disclaimer: I am one of the developers of the library.