Old school D3 from simpler times
WebVis contributions bubble chart
(This gist contains server-side code. In order to see it running, you should open it on WebVis.)
This example displays a simple bubble chart, in which each bubble is sized according to the amount of contributions a certain user has made to the WebVis laboratory.
Data is read live from the underlying Neo4j graph DB through PHP.
The bubble chart is implemented as a force layout with a non-overlapping constraint (see this example), initialized with a radial displacement of the circles. A simpler, more efficient implementation using a circle packing layout can be found in this example.