Piccolo is a toolkit that supports the development of 2D structured graphics programs in general, and Zoomable User Interfaces (ZUIs) in particular. There are currently three versions: Piccolo.Java, Piccolo.NET and PocketPiccolo.NET (for the .NET Compact Framework). This makes it easy for Java and C# programmers, even those targeting PDAs, to build their own animated graphical applications with zooming, multiple cameras, layers, images, etc. Homepage
There are sample applications (mostly Java at the moment), and the download includes the source code of the library released under the BSD license.