The Qyoto/Kimono are languages bindings that will allow C# (or any other .NET language) to be used to write Qt/KDE programs. Compilation and installation instructions: http://ekarchive.elikirk.com/david/qyoto/index.php?option=com_content&task=view&id=25&Itemid=58 Reproducible: Always Steps to Reproduce:
It's shipped as part of kde.org's kdebindings package. Not yet available in the repository.
kde-base/kdebindings-csharp is what you probably want, in tree with kde 4.3 :)