Tk Drag and Drop is an extension for Tcl/Tk to add native drag and drop capabilities to the Tk toolkit. It is designed for Tk versions 8.3.3 and higher. Native drag and drop are supported under Microsoft Windows (XP, Vista, 7), Mac OS X Leopard (Cocoa framework), and Linux (XDND, drag support missing).
Sc21 is a MacOS X framework for integrating the Coin high-level 3D framework into Cocoa applications. The combination of Coin and Sc21 (pronounced "Scandium", like the element) makes it possible to create native, high-performance 3D graphics application on MacOS X based on the industry standard Open Inventor API. Sc21 is written in Objective-C++ and comes as a Mac framework bundle. It also includes a custom Interface Builder palette which lets developers drag and drop the most important components into their project.