for intance, Yifan hu (U Florida faculty, i think) maintains a spectacular gallery of very large graphs comprised of millions of nodes, all rendered using GraphViz (persisted and input to GraphViz as incidence matrices):
http://yifanhu.net/GALLERY/GRAPHS/index2.html
The graphs in the gallery i liked to above were rendered using sfdp, one of the 5-6 layout engines in GraphViz, and which is the GraphViz engine of choice for very large undirected graphs not limited to a particular layout geometry
agree completely; GraphViz is extraordinary.
for intance, Yifan hu (U Florida faculty, i think) maintains a spectacular gallery of very large graphs comprised of millions of nodes, all rendered using GraphViz (persisted and input to GraphViz as incidence matrices): http://yifanhu.net/GALLERY/GRAPHS/index2.html
The graphs in the gallery i liked to above were rendered using sfdp, one of the 5-6 layout engines in GraphViz, and which is the GraphViz engine of choice for very large undirected graphs not limited to a particular layout geometry