We present a prototype of a software tool for exploration of multiple combinatorial optimisation problems in large real-world and synthetic complex networks. Our tool, called GraphCombEx (an acronym of Graph Combinatorial Explorer), provides a unified framework for scalable computation of high-quality suboptimal solutions and bounds for a number of widely studied combinatorial optimisation problems in large graphs. The problems currently supported include: maximum clique, graph colouring, maximum independent set, minimum vertex clique covering, minimum dominating set, as well as the longest simple cycle problem. Suboptimal solutions and intervals for optimal objective values are estimated using scalable heuristics. GraphCombEx has previously or currently been tested in scenarios of exploring synthetic graph models, as well as real-world networks ranging from social network samples, biological networks, to very large networks from the SNAP network data repository. The tool has already been successfully used to support a number of recent studies and is particularly beneficial in exploring the combinatorial properties of previously unseen network data, before applying more sophisticated custom optimisation algorithms.
Planarity Testing and Embedding Maurizio Patrignani Crossings and Planarization Christoph Buchheim, Markus Chimani, Carsten Gutwenger, Michael Junger, and Petra Mutzel Symmetric Graph Drawing Peter Eades and Seok-Hee Hong Proximity Drawings Giuseppe Liotta Tree Drawing Algorithms Adrian Rusu Planar Straight-Line Drawing Algorithms Luca Vismara Planar Orthogonal and Polyline Drawing Algorithms Christian A. Duncan and Michael T. Goodrich Spine and Radial Drawings Emilio Di Giacomo, Walter Didimo, and Giuseppe Liotta Circular Drawing Algorithms Janet M. Six and Ioannis G. Tollis Rectangular Drawing Algorithms Takao Nishizeki and Md. Saidur Rahman Simultaneous Embedding of Planar Graphs Thomas Blasius, Stephen G. Kobourov, and Ignaz Rutter Force-Directed Drawing Algorithms Stephen G. Kobourov Hierarchical Drawing Algorithms Patrick Healy and Nikola S. Nikolov Three-Dimensional Drawings Vida Dujmovic and Sue Whitesides Labeling Algorithms Konstantinos G. Kakoulis and Ioannis G. Tollis Graph Markup Language (GraphML) Ulrik Brandes, Markus Eiglsperger, Jurgen Lerner, and Christian Pich The Open Graph Drawing Framework (OGDF) Markus Chimani, Carsten Gutwenger, Michael Junger, Gunnar W. Klau, Karsten Klein, and Petra Mutzel GDToolkit Giuseppe Di Battista and Walter Didimo PIGALE Hubert de Fraysseix and Patrice Ossona de Mendez Biological Networks Christian Bachmaier, Ulrik Brandes, and Falk Schreiber Computer Security Olga Ohrimenko, Charalampos Papamanthou, and Bernardo Palazzi Graph Drawing for Data Analytics Stephen G. Eick Graph Drawing and Cartography Alexander Wolff Graph Drawing in Education Stina Bridgeman Computer Networks Giuseppe Di Battista and Massimo Rimondini Social Networks Ulrik Brandes, Linton C. Freeman, and Dorothea Wagner Index  Gephi is an open source software for graph and network analysis. It uses a 3D render engine to display large networks in real-time and to speed up the exploration. A flexible and multi-task architecture brings new possibilities to work with complex data sets and produce valuable visual results. We present several key features of Gephi in the context of interactive exploration and interpretation of networks. It provides easy and broad access to network data and allows for spatializing, filtering, navigating, manipulating and clustering. Finally, by presenting dynamic features of Gephi, we highlight key aspects of dynamic network visualization.