Squeak is an OpenSource and super-portable implementation of a multi-media capable Smalltalk-80 based object-oriented programming environment. It is written entirely in Smalltalk and has a high-performance VM, created by compiling the Smalltalk VM code into efficient and portable C code. It now uses the Self language's Morphic User Interface but still provides the original MVC GUI as well.
Light-Weight Visual Components Library (LwVCL) is a powerful, small, fast, efficient, framework of visual components that provides a rich set of customizable, flexible user interface components. There are versions for J2SE/J2ME Personal Profile, J2ME MIDP, .NET, and SWT. This provides a unified GUI framework for different platforms that provides the same API, the same concepts, and the same look and feel.
Bambookit GUI is a completely XML-scriptable user interface to build real-time interactive Web application front-ends. Applications occupy 100 Kb of device memory and run on any Java-enabled browser. Users can move windows, resize containers, scroll and sort tables, lists, trees, see real-time data display, use a layout manager, and more. All rendering and event handling is managed in the XML scripts.