graphviz

Graphviz is open-source graph visualization software that renders structural information as diagrams of nodes and edges. It accepts descriptions written in the DOT language and can produce graphics in multiple formats, including PNG, SVG, PDF, EPS, and PostScript. It runs on major platforms such as Linux, Windows, and macOS and is usable from the command line or integrated into other tools.

Core to Graphviz are its layout programs, including dot, neato, fdp, sfdp, twopi, and circo. Each program applies a different layout algorithm: dot creates hierarchical or layered drawings suitable for directed graphs; neato and fdp use force-directed methods for general graphs; sfdp handles large graphs; twopi produces radial layouts; circo arranges nodes in circular layouts. Descriptions in DOT specify nodes, edges, subgraphs, and attributes that influence appearance and placement.

Graphviz supports automatic layout with extensive attribute control over nodes and edges, including shapes, colors, fonts, and labels. Subgraphs and clusters enable grouping, while constraints refine how elements are positioned. Output can be a variety of vector or raster formats, suitable for inclusion in documents, web pages, or software diagrams.

Graphviz is used for software architecture and documentation, network diagrams, database schemas, and visualizing workflows. It is available as a standalone tool and has bindings for several programming languages, such as Python, Ruby, and Perl, allowing programmatic generation of DOT descriptions.

Originally developed at AT&T Research, Graphviz is distributed under a permissive open-source license and is maintained by a community of contributors alongside its core developers.