Developer Express is a component vendor with add-ons for Visual Studio and Delphi. It has offered a library of components for Silverlight for some time, and a separate set for WPF (Windows Presentation Foundation), but now says that Silverlight and WPF are close enough that it can merge the two into a single codebase to be called XPF (Express Presentation Framework). CTO Julian Bucknall says:
Silverlight in v4 has the ability to create desktop applications that aren’t sandboxed into triviality. In fact, Silverlight, more than ever, resembles a WPF-lite on the desktop side, to the extent of pundits considering their eventual merging. At long last it is possible to write one set of non-trivial code and compile it both for Silverlight and for WPF without having to reinvent so many wheels on the Silverlight side (and to a much lesser extent on the WPF side).
Even though Visual Studio 2010 is only just released, DevExpress is focusing all its new Silverlight and WPF development on the new platform and IDE:
Of course it’s in Bucknall’s interests to move developers on; he’s keen to sell upgrades. I still find this interesting. Like him, I find Visual Studio 2010 a major advance on earlier versions. More significant though is the idea of a common WPF and Silverlight codebase, though presumably still with added capabilities when running on WPF. I don’t think Windows-only development is dead; the success of Windows 7 may even stimulate the market for applications that take advantage of its new features. That said, for the large subset of applications where cross-platform is desirable, Silverlight seems to me a better choice than WPF.