ThyAPI

Web site: http://sourceforge.net/projects/thyapi/

License: LGPL

ThyAPI is a framework for creating rich applications. It needs a server component but will work with any server-side language that supports XML-RPC. (Currently only a PHP back end exists.) The API is similar to client GUI frameworks, such as Java's Swing, and includes a number of widgets, including a rich text editor, a calendar, dialog boxes, and windows. ThyAPI also supports drag-and-drop support, animations, and sound playback. (Sound playback uses the Flash plug-in.)