Gephi

Gephi (http://gephi.org/)


Gephi is an open-source and multiplatform software distributed under the dual license CDDL 1.0 and GNU General Public License v3.

Layout algorithms give the shape to the graph. Gephi provides state-of-the-art algorithms layout algorithms, both for efficiency and quality. The Layout palette allows user to change layout settings while running, and therefore dramatically increase user feedback and experience: Force-based algorithms or Multi-level algorithms (graph coarsening). 

Video demonstration : 

https://gephi.org/videos/