Languages/QtSharp
Qt# was an attempt to create a set of classes that bind the C# language to the Qt toolkit. The bindings appear abandoned based on the Qt# home page.
The Qyoto/Kimono project are SMOKE based bindings which use the mono C# compiler for use with Qt and KDE that are very similar to C++/Qt syntax but with the addition of the unique syntactic constructs of C#. Because .NET is a multi-language VM, a variety of languages should be able to access the bindings.
You can get the latest code via svn://anonsvn.kde.org/home/kde/trunk/KDE/kdebindings or use the KDE bindings module from the KDE 4.x releases.
Mono is an open source implementation of the .NET Development Framework.
Discussion on the Mono Mailinglist about the project progress.