sheetjs-clone/misc/legend.dot

digraph G {
	graph [mindist=0];
	labelloc=t;
	label="Legend"

	subgraph cluster_0 {
		label="Supported Format Types"
		color="white"
		XL[label="Excel",style=filled,color=green];
		CSF[label="JS",shape=doublecircle];
		OLD[label="Other",style=filled,color=cyan];
		{ edge[style=invis] XL -> CSF -> OLD[constraint=false]}
	}

	subgraph cluster_1 {
		label="Workbook Format Conversions (blue arrow)"
		color="white"
		x1i[label="XLSX"]
		c1[shape=doublecircle,label="JS"];
		x1o[label="XLSB"]
		{ edge[color=blue]
			x1i->c1[constraint=false,label="read"]
			c1->x1o[constraint=false,label="write"];
		}
	}

	subgraph cluster_2 {
		label="Single-Worksheet Format Conversions (green arrow)"
		color="white"
		x2i[label="SYLK"]
		c2[shape=doublecircle,label="JS"];
		x2o[label="CSV"]
		{ edge[color=aquamarine4]
			x2i->c2[constraint=false,label="read"]
			c2->x2o[constraint=false,label="write"];
		}
	}

	{ edge[style=invis] XL -> x1i -> x2i; }
	{ edge[style=invis] CSF -> c1 -> c2; }
	{ edge[style=invis] OLD -> x1o -> x2o; }
}