### Graphviz:

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<blockquote><p>AT&T Labs Tools for viewing and interacting with graph diagrams.<br />Graph visualization is a way of representing structural information as diagrams of abstract graphs and networks. Automatic graph drawing has many important applications in software engineering, database and web design, networking, and in visual interfaces for many other domains. Graphviz is open source graph visualization software. It has several main graph layout programs.</p></blockquote>

DOT

DOT is a plain text graph description language. It is a simple way of describing graphs that both humans and computer programs can use. DOT graphs are typically files that end with the .gv (or .dot) extension. The .gv extension is preferred, as the .dot file extension is used by Microsoft Office 2003.

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