Graphviz is a package of open source tools initiated by AT&T Labs Research for drawing graphs. Graph is a structural representation of data and is composed of vertices and edges. Some of the popular forms of graph diagrams are sociograms, state diagrams, flowcharts and computer network diagrams.
Graphviz takes the description of graphs in a simple text language called DOT and creates graphs in formats like SVG, PDF and Postscript. Graphviz includes a command line tool called dot which creates graphs in various output formats. It also includes multiple layout engines like circo, twopi, fdp, neato, etc, and a graphical user interface called dotty to visualise and edit graphs. Since we are interested in the DSL aspect of Graphviz, we will focus on DOT and its capabilities. For more information about various utilities bundled with Graphviz, please take a look at the References given at the end of the article.