NodeBox is an application for creating 2D graphics and visualizations. It provides a visual and process-based editor for an underlying Python-based analysis and visualisation package. It is developer-described as a generative design app and this really taps into the serendipitous nature of the environment. The user constructs models and can tweak them in real time via the interface and see the resulting changes too the output.
It has been described as being "similar to Processing, but without all the interactivity".