<graphviz>
digraph unix {
	size="6,6";
	node [color=lightblue2, style=filled];
	"5th Edition" -> "6th Edition";
"5th Edition" -> "PWB 1.0";
	"6th Edition" -> "LSX";
	"6th Edition" -> "1 BSD";
	"6th Edition" -> "Mini Unix";
	"6th Edition" -> "Wollongong";
	"6th Edition" -> "Interdata";
	"Interdata" -> "Unix/TS 3.0";
	"Interdata" -> "PWB 2.0";
	"Interdata" -> "7th Edition";
	"7th Edition" -> "8th Edition";
	"7th Edition" -> "32V";
	"7th Edition" -> "V7M";
	"7th Edition" -> "Ultrix-11";
	"7th Edition" -> "Xenix";
	"7th Edition" -> "UniPlus+";
	"V7M" -> "Ultrix-11";
"8th Edition" -> "9th Edition";
	"1 BSD" -> "2 BSD";
	"2 BSD" -> "2.8 BSD";
	"2.8 BSD" -> "Ultrix-11";
	"2.8 BSD" -> "2.9 BSD";
	"32V" -> "3 BSD";
	"3 BSD" -> "4 BSD";
	"4 BSD" -> "4.1 BSD";
	"4.1 BSD" -> "4.2 BSD";
	"4.1 BSD" -> "2.8 BSD";
	"4.1 BSD" -> "8th Edition";
	"4.2 BSD" -> "4.3 BSD";
	"4.2 BSD" -> "Ultrix-32";
"PWB 1.0" -> "PWB 1.2";
	"PWB 1.0" -> "USG 1.0";
	"PWB 1.2" -> "PWB 2.0";
	"USG 1.0" -> "CB Unix 1";
	"USG 1.0" -> "USG 2.0";
	}
</graphviz>