The neighbours were extracted from the RIB dumps generated by RIS project. The data was collected at the biggest exchanges around the world on Oct 1, 2014. Only announced IPv6 prefixes were taken into account (graph for IPv4 version also exists)
The graph is undirected. Size of the node reflects how many neighbours AS has. Thickness of the edge depends on how many prefixes RIS saw with these neighbours in AS path.
Graph statistics: 9166 nodes, 41276 edges
Raw data (large size!): neighbours list, AS clusters by holder, Gephi graph