Waterbear is a toolkit for creating drag-and-drop programming languages, with some example languages you can play around with and learn from. The goal is to make it easy to wrap other existing languages with Waterbear blocks to create draggable, snappable syntaxes for them.
Drag and drop (D&D) is an intuitive GUI gesture used for
transferring data from one GUI component to another. This second
article in the drag and drop series explores how you can transfer
data besides text and discusses the issues involved with developing
a library of D&D-enabled project Swing components. (4,400