Tributary is a tool that allows you to prototype responsively — that is, to see the result of your code immediately as you play with it. The standard package is found at the first link below. The following links are different versions, or “end points”, that are set up to specific use cases as described below.
I’ll be updating this list with example experiments for each end point.
Delta – Create Transitions with Fixed Endpoints
HourGlass – Experiment with Continuous Loops/Animation and User Input in D3
Cypress – Experiment with Continuous Loops/Animation and User Input in HTML5
Flow – Create Visualizations Responsive to Audio Files
Reptile – Create Tiled Patterns