libTISCH is a framework for easy development of multi-touch applications. It contains tools for video processing, calibration, gesture recognition and, most importantly, a GUI toolkit with widgets that utilize the multi-touch gestures detected by the lower layers. It runs on Linux, Mac OS X, and Windows.
Sigma Visual builder is a WYSIWYG tool for rapid Web application design and involved script programming. With this powerful builder, Web applications can be developed using only drag and drop, just like what you do in VB or Delphi. More than 35 common AJAX components, including Tabs, Dialog, TreeGrid, TimeLine, and many other Web GUI components are supported. Its rich client-side API works with any backend (such as PHP, .NET, Java, or Python) or static HTML pages. The generated application has wide cross-browser compatibility.
IT Mill Toolkit is a server-side RIA (Rich Internet Application) library that provides a versatile set of AJAX widgets for Java programmers. Applications are programmed in Java and executed server-side. At the client-side (i.e. in the browser), enhanced GWT widgets are used for presentation.
Wicket Web Beans (WWB) is an Apache Wicket component toolkit for displaying and editing POJOs that conform to the JavaBeans specification. Web pages are automatically generated based on bean properties and certain conventions. If necessary, the layout, editability, and actions of these pages can be customized on an exception basis. In other words, the toolkit normally does what you'd expect, but when it doesn't, you can override its behavior.
The Ecere SDK is a cross-platform toolkit for building software applications. It currently runs on Windows, Linux, Mac OS X (through X11), FreeBSD, and the Android OS. It should run on other Unix platforms with minor testing/tweaking. With the Ecere SDK, you can develop applications once and deploy them on all supported platforms alongside a lightweight runtime environment. It introduces eC, an object oriented language derived from and fully compatible with C, compromising neither runtime performance nor ease of use. A built-in 3D engine supporting both Direct3D and OpenGL is fully integrated.