Click and drag nodes to move them around. Typically, nodes may only pass through like-colored wires. White nodes may pass through any color, and any node may pass through white wires. Black nodes cannot pass through any colors, and nothing may pass through black wires.
In it's current form, ColorTangle has been "done" for almost 2 years. My work commitments (working for a social games company) have kept me pretty busy, so it's great to finally get this thing out there!