DIMACS is a file format for storing a single undirected graph. It is has both text and binary variants.

The commands GraphTheory[ImportGraph] and GraphTheory[ExportGraph] can read from and write to the text-based version of this format.

The general-purpose commands Import and Export also support this format.

$G≔\mathrm{Import}\left(''example/coxeter.col''\,\mathrm{base}=\mathrm{datadir}\right)$

$G≔\mathrm{Graph\; 1:\; an\; undirected\; unweighted\; graph\; with\; 28\; vertices\; and\; 42\; edge(s)}$

$\mathrm{GraphTheory}:-\mathrm{DrawGraph}\left(G\,\mathrm{style}=\mathrm{spring}\right)$