Graphviz

Graphviz is an open source graph visualization software. It reads a text file description of a graph and generates an image automatically.

Usage

Graphviz provides many binaries for building the image:

binary	description
`dot`	filter for drawing directed graphs
`neato`	filter for drawing undirected graphs
`twopi`	filter for radial layouts of graphs
`circo`	filter for circular layout of graphs
`fdp`	filter for drawing undirected graphs
`sfdp`	filter for drawing large undirected graphs
`patchwork`	filter for squarified tree maps
`osage`	filter for array-based layouts

I mostly use dot.

dot -Tpng graph.dot -o graph.png

hello.dot

digraph {
    hello -> world
}

dot -Tpng hello.dot -o hello.png

hello.png

Hello, Graphviz!

Attribute	Description
rankdir	Set direction of graph layout (`LR` / `TB`)
label	Text label attached to objects