GraphvizFiddle (viz.js 1.0.1 release, with ortho fix)

GraphvizFiddle draws DOT language [directed] graphs, see DOT User's Guide (on http://graphviz.org/).
It is an online code editor and playground for Graphviz dot layout tool, see blog posting for details.

/*
    fsm for JSON "number" (http://tools.ietf.org/search/rfc4627#page-4)
*/
digraph G {
  size="12,12"; rankdir=LR;

node[style=invis] A;B;C;D;E;F;G; node[style=solid];

{ rank=same; "A"; "F"; "1"; } { rank=same; "E"; "G"; "11" }
  { rank=same; "B"; "2"; } { rank=same; "C"; "4"; } { rank=same; "D"; "7"; }

"F" -> "G" [label="number\n(rfc4627)"]; 
  "A" -> "B" [label="[minus]"]; "B" -> "C" [label="int"]; 
  "C" -> "D" [label="[frac]"]; "D" -> "E" [label="[exp]"];
  "1" -> "2" [label=""]; "1" -> "2" [label="%x2D"]; "2" -> "4" [label="%x30"];
  "2" -> "3" [label="%x31-39"]; "3" -> "3" [label="%x30-39"];
  "3" -> "4" [label=""]; "4" -> "7" [label=""]; "4" -> "5" [label="%x2E"];
  "5" -> "6" [label="%x30-39"]; "6" -> "6" [label="%x30-39"];
  "6" -> "7" [label=""]; "7" -> "11" [label=""];
  "7" -> "8" [label="%x65"]; "7" -> "8" [label="%x45"];
  "8" -> "9" [label=""]; "8" -> "9" [label="%x2B"]; "8" -> "9" [label="%x2D"];
  "9" -> "10" [label="%x30-39"];
  "10" -> "10" [label="%x30-39"]; "10" -> "11" [label=""];
}

// complete f(x)=x² mod 221 graph for Pollard's rho method
digraph G { size="64,8";rankdir=BT;
0->0;1->1;2->4;3->9;4->16;5->25;6->36;7->49;8->64;9->81;10->100;11->121;15->4;
13->169;14->196;12->144;16->35;17->68;18->103;19->140;20->179;21->220;22->42;
23->87;24->134;25->183;26->13;27->66;28->121;29->178;30->16;31->77;32->140;
33->205;34->51;35->120;36->191;37->43;38->118;39->195;40->53;41->134;42->217;
43->81;44->168;45->36;46->127;47->220;48->94;49->191;50->69;51->170;52->52;
53->157;54->43;55->152;56->42;57->155;58->49;59->166;60->64;61->185;62->87;
63->212;64->118;65->26;66->157;67->69;68->204;69->120;70->38;71->179;72->101;
73->25;74->172;75->100;76->30;77->183;78->117;79->53;80->212;81->152;82->94;
83->38;84->205;85->153;86->103;87->55;88->9;89->186;90->144;91->104;92->66;
93->30;94->217;95->185;96->155;97->127;98->101;99->77;100->55;101->35;102->17;
103->1;104->208;105->196;106->186;107->178;108->172;109->168;110->166;111->166;
112->168;113->172;114->178;115->186;116->196;117->208;118->1;119->17;120->35;
121->55;122->77;123->101;124->127;125->155;126->185;127->217;128->30;129->66;
130->104;131->144;132->186;133->9;134->55;135->103;136->153;137->205;138->38;
139->94;140->152;141->212;142->53;143->117;144->183;145->30;146->100;147->172;
148->25;149->101;150->179;151->38;152->120;153->204;154->69;155->157;156->26;
157->118;158->212;159->87;160->185;161->64;162->166;163->49;164->155;165->42;
166->152;167->43;168->157;169->52;170->170;171->69;172->191;173->94;174->220;
175->127;176->36;177->168;178->81;179->217;180->134;181->53;182->195;183->118;
184->43;185->191;186->120;187->51;188->205;189->140;190->77;191->16;192->178;
193->121;194->66;195->13;196->183;197->134;198->87;199->42;200->220;201->179;
202->140;203->103;204->68;205->35;206->4;207->196;208->169;209->144;210->121;
211->100;212->81;213->64;214->49;215->36;216->25;217->16;218->9;219->4;220->1;}

digraph "unix" {
	graph [	fontname = "Helvetica-Oblique",
		fontsize = 36,
		label = "\n\n\n\nObject Oriented Graphs\nStephen North, 3/19/93",
		size = "6,6" 
//		size = "9,9" 
             ];
	node [	shape = polygon,
		sides = 4,
		distortion = "0.0",
		orientation = "0.0",
		skew = "0.0",
		color = white,
		style = filled,
		fontname = "Helvetica-Outline" ];
	"5th Edition" [sides=9, distortion="0.936354", orientation=28, skew="-0.126818", color=salmon2];
	"6th Edition" [sides=5, distortion="0.238792", orientation=11, skew="0.995935", color=deepskyblue];
	"PWB 1.0" [sides=8, distortion="0.019636", orientation=79, skew="-0.440424", color=goldenrod2];
	LSX [sides=9, distortion="-0.698271", orientation=22, skew="-0.195492", color=burlywood2];
	"1 BSD" [sides=7, distortion="0.265084", orientation=26, skew="0.403659", color=gold1];
	"Mini Unix" [distortion="0.039386", orientation=2, skew="-0.461120", color=greenyellow];
	Wollongong [sides=5, distortion="0.228564", orientation=63, skew="-0.062846", color=darkseagreen];
	Interdata [distortion="0.624013", orientation=56, skew="0.101396", color=dodgerblue1];
	"Unix/TS 3.0" [sides=8, distortion="0.731383", orientation=43, skew="-0.824612", color=thistle2];
	"PWB 2.0" [sides=6, distortion="0.592100", orientation=34, skew="-0.719269", color=darkolivegreen3];
	"7th Edition" [sides=10, distortion="0.298417", orientation=65, skew="0.310367", color=chocolate];
	"8th Edition" [distortion="-0.997093", orientation=50, skew="-0.061117", color=turquoise3];
	"32V" [sides=7, distortion="0.878516", orientation=19, skew="0.592905", color=steelblue3];
	V7M [sides=10, distortion="-0.960249", orientation=32, skew="0.460424", color=navy];
	"Ultrix-11" [sides=10, distortion="-0.633186", orientation=10, skew="0.333125", color=darkseagreen4];
	Xenix [sides=8, distortion="-0.337997", orientation=52, skew="-0.760726", color=coral];
	"UniPlus+" [sides=7, distortion="0.788483", orientation=39, skew="-0.526284", color=darkolivegreen3];
	"9th Edition" [sides=7, distortion="0.138690", orientation=55, skew="0.554049", color=coral3];
	"2 BSD" [sides=7, distortion="-0.010661", orientation=84, skew="0.179249", color=blanchedalmond];
	"2.8 BSD" [distortion="-0.239422", orientation=44, skew="0.053841", color=lightskyblue1];
	"2.9 BSD" [distortion="-0.843381", orientation=70, skew="-0.601395", color=aquamarine2];
	"3 BSD" [sides=10, distortion="0.251820", orientation=18, skew="-0.530618", color=lemonchiffon];
	"4 BSD" [sides=5, distortion="-0.772300", orientation=24, skew="-0.028475", color=darkorange1];
	"4.1 BSD" [distortion="-0.226170", orientation=38, skew="0.504053", color=lightyellow1];
	"4.2 BSD" [sides=10, distortion="-0.807349", orientation=50, skew="-0.908842", color=darkorchid4];
	"4.3 BSD" [sides=10, distortion="-0.030619", orientation=76, skew="0.985021", color=lemonchiffon2];
	"Ultrix-32" [distortion="-0.644209", orientation=21, skew="0.307836", color=goldenrod3];
	"PWB 1.2" [sides=7, distortion="0.640971", orientation=84, skew="-0.768455", color=cyan];
	"USG 1.0" [distortion="0.758942", orientation=42, skew="0.039886", color=blue];
	"CB Unix 1" [sides=9, distortion="-0.348692", orientation=42, skew="0.767058", color=firebrick];
	"USG 2.0" [distortion="0.748625", orientation=74, skew="-0.647656", color=chartreuse4];
	"CB Unix 2" [sides=10, distortion="0.851818", orientation=32, skew="-0.020120", color=greenyellow];
	"CB Unix 3" [sides=10, distortion="0.992237", orientation=29, skew="0.256102", color=bisque4];
	"Unix/TS++" [sides=6, distortion="0.545461", orientation=16, skew="0.313589", color=mistyrose2];
	"PDP-11 Sys V" [sides=9, distortion="-0.267769", orientation=40, skew="0.271226", color=cadetblue1];
	"USG 3.0" [distortion="-0.848455", orientation=44, skew="0.267152", color=bisque2];
	"Unix/TS 1.0" [distortion="0.305594", orientation=75, skew="0.070516", color=orangered];
	"TS 4.0" [sides=10, distortion="-0.641701", orientation=50, skew="-0.952502", color=crimson];
	"System V.0" [sides=9, distortion="0.021556", orientation=26, skew="-0.729938", color=darkorange1];
	"System V.2" [sides=6, distortion="0.985153", orientation=33, skew="-0.399752", color=darkolivegreen4];
	"System V.3" [sides=7, distortion="-0.687574", orientation=58, skew="-0.180116", color=lightsteelblue1];
	"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";
	"CB Unix 1" -> "CB Unix 2";
	"CB Unix 2" -> "CB Unix 3";
	"CB Unix 3" -> "Unix/TS++";
	"CB Unix 3" -> "PDP-11 Sys V";
	"USG 2.0" -> "USG 3.0";
	"USG 3.0" -> "Unix/TS 3.0";
	"PWB 2.0" -> "Unix/TS 3.0";
	"Unix/TS 1.0" -> "Unix/TS 3.0";
	"Unix/TS 3.0" -> "TS 4.0";
	"Unix/TS++" -> "TS 4.0";
	"CB Unix 3" -> "TS 4.0";
	"TS 4.0" -> "System V.0";
	"System V.0" -> "System V.2";
	"System V.2" -> "System V.3";
}

digraph g {
graph [
rankdir = "LR" 
//rankdir = "TB"
];
node [
fontsize = "16"
shape = "ellipse"
];
edge [
];
"node0" [
label = "<f0> 0x10ba8| <f1>"
shape = "record"
];
"node1" [
label = "<f0> 0xf7fc4380| <f1> | <f2> |-1"
shape = "record"
];
"node2" [
label = "<f0> 0xf7fc44b8| | |2"
shape = "record"
];
"node3" [
label = "<f0> 3.43322790286038071e-06|44.79998779296875|0"
shape = "record"
];
"node4" [
label = "<f0> 0xf7fc4380| <f1> | <f2> |2"
shape = "record"
];
"node5" [
label = "<f0> (nil)| | |-1"
shape = "record"
];
"node6" [
label = "<f0> 0xf7fc4380| <f1> | <f2> |1"
shape = "record"
];
"node7" [
label = "<f0> 0xf7fc4380| <f1> | <f2> |2"
shape = "record"
];
"node8" [
label = "<f0> (nil)| | |-1"
shape = "record"
];
"node9" [
label = "<f0> (nil)| | |-1"
shape = "record"
];
"node10" [
label = "<f0> (nil)| <f1> | <f2> |-1"
shape = "record"
];
"node11" [
label = "<f0> (nil)| <f1> | <f2> |-1"
shape = "record"
];
"node12" [
label = "<f0> 0xf7fc43e0| | |1"
shape = "record"
];
"node0":f0 -> "node1":f0 [
id = 0
];
"node0":f1 -> "node2":f0 [
id = 1
];
"node1":f0 -> "node3":f0 [
id = 2
];
"node1":f1 -> "node4":f0 [
id = 3
];
"node1":f2 -> "node5":f0 [
id = 4
];
"node4":f0 -> "node3":f0 [
id = 5
];
"node4":f1 -> "node6":f0 [
id = 6
];
"node4":f2 -> "node10":f0 [
id = 7
];
"node6":f0 -> "node3":f0 [
id = 8
];
"node6":f1 -> "node7":f0 [
id = 9
];
"node6":f2 -> "node9":f0 [
id = 10
];
"node7":f0 -> "node3":f0 [
id = 11
];
"node7":f1 -> "node1":f0 [
id = 12
];
"node7":f2 -> "node8":f0 [
id = 13
];
"node10":f1 -> "node11":f0 [
id = 14
];
"node10":f2 -> "node12":f0 [
id = 15
];
"node11":f2 -> "node1":f0 [
id = 16
];
}

digraph G {
	graph [center=1 rankdir=LR bgcolor="#808080"]
	edge [dir=none]
	node [width=0.3 height=0.3 label=""]
	{ node [shape=circle style=invis]
		1 2 3 4 5 6 7 8  10 20 30 40 50 60 70 80
	}
	{ node [shape=circle]
		a b c d e f g h  i j k l m n o p  q r s t u v w x
	}
	{ node [shape=diamond]
		A B C D E F G H  I J K L M N O P  Q R S T U V W X
	}
	1 -> a -> {A B} [color="#0000ff"]
//	1 -> a -> {A B} [color="#c0c0ff"]
	2 -> b -> {B A} [color="#ff0000"]
	3 -> c -> {C D} [color="#ffff00"]
	4 -> d -> {D C} [color="#00ff00"]
	5 -> e -> {E F} [color="#000000"]
	6 -> f -> {F E} [color="#00ffff"]
	7 -> g -> {G H} [color="#ffffff"]
	8 -> h -> {H G} [color="#ff00ff"]
	{ edge [color="#ff0000:#0000ff"]
		A -> i -> {I K}
		B -> j -> {J L}
	}
	{ edge [color="#00ff00:#ffff00"]
		C -> k -> {K I}
		D -> l -> {L J}
	}
	{ edge [color="#00ffff:#000000"]
		E -> m -> {M O}
		F -> n -> {N P}
	}
	{ edge [color="#ff00ff:#ffffff"]
		G -> o -> {O M}
		H -> p -> {P N}
	}
	{ edge [color="#00ff00:#ffff00:#ff0000:#0000ff"]
		I -> q -> {Q U}
		J -> r -> {R V}
		K -> s -> {S W}
		L -> t -> {T X}
	}
	{ edge [color="#ff00ff:#ffffff:#00ffff:#000000"]
		M -> u -> {U Q}
		N -> v -> {V R}
		O -> w -> {W S}
		P -> x -> {X T}
	}
	{ edge [color="#ff00ff:#ffffff:#00ffff:#000000:#00ff00:#ffff00:#ff0000:#0000ff"]
		Q -> 10
		R -> 20
		S -> 30
		T -> 40
		U -> 50
		V -> 60
		W -> 70
		X -> 80
	}
}