Review on jsPlumb Toolkit by Quintin Gore

It's free! And you can create very nice looking connections between nodes in real time (no need of polling). I'm using it mainly for creating UI elements like buttons and links but there are also connectors that connect two existing objects together so they form one object by clicking them both at once.jsplumber makes sure all browsers work without any issue since we're targeting multiple browser/OS versions now. You should give this tool a try if your project requires good looking node layout - you won't regret adding these tools into your workflow. We needed something fast to prototype our web interface components quickly while still being able to change everything later when designing final product.