Gephi is an open-source network analysis and visualization software package written in Java on the NetBeans platform - wikipedia 
Graph representing the metadata of thousands of archive documents, documenting the social network of hundreds of League of Nations personals - wikimedia.org
# Features
Gephi is a tool for data analysts and scientists keen to explore and understand graphs. Like Photoshop™ but for graph data, the user interacts with the representation, manipulate the structures, shapes and colors to reveal hidden patterns - gephi.org
A graph drawing interface (Gephi 0.9.1)]]Software, systems, and providers of systems for drawing graphs includ
- wikimedia.org
The goal is to help data analysts to make hypothesis, intuitively discover patterns, isolate structure singularities or faults during data sourcing. It is a complementary tool to traditional statistics, as visual thinking with interactive interfaces is now recognized to facilitate reasoning. This is a software for Exploratory Data Analysis, a paradigm appeared in the Visual Analytics field of research.
# Real-time visualization
Profit from the fastest graph visualization engine to speed-up understanding and pattern discovery in large graphs. Powered by its ad-hoc OpenGL engine, Gephi is pushing the envelope on how interactive and efficient network exploration can be.
Networks up to 100,000 nodes and 1,000,000 edges Iterate through visualization using dynamic filtering Rich tools for meaningful graph manipulation
# Layout
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.
# Metrics
The statistics and metrics framework offer the most common metrics for social network analysis (SNA) and scale-free networks.
- Betweenness Centrality - Closeness - Diameter - Clustering Coefficient - PageRank - Community detection (Modularity) - Random generators - Shortest path
# Networks over time
Gephi is a the forefront of innovation with dynamic graph analysis. Users can visualize how a network evolve over time by manipulating the embedded timeline.
Import temporal graph with the GEXF file format Run metrics over time (clustering coefficient) Graph streaming ready
# Create cartography
Use ranking or partition data to make meaningful the network representation. Customize colors, size or labels to bring sense to the network representation. The vectorial preview module lets you put the final touch and care about aesthetics before explorting in SVG or PDF.
# See also - Graphviz