Discrete Graph Formats

"Graphlet" — GML graph data format (.gml)

"DOT" — DOT graph data format (.gv, .dot)

"GraphML" — GraphML data format (.graphml)

"GXL" — GXL graph data format (.gxl)

"DIMACS" — DIMACS graph data format (.col, .col.b)

"Graph6" — dense graph data format (.g6)

"Sparse6" — sparse graph format (.s6)

"LEDA" — LEDA format (.gw, .lgr)

"Pajek" — Pajek graph data (.net)

"TGF" — trivial graph format (.tgf)

Matrix Formats

"MAT" — Matlab/Octave data format (.mat)

"MTX" — Matrix Market sparse matrix format (.mtx)

"HarwellBoeing" — Harwell–Boeing sparse matrix formats