GraphViz-Dokumentation: http://www.graphviz.org/Documentation.php

digraph G {A->B; A->C; B->C} <graphviz> digraph G {A->B; A->C; B->C} </graphviz>

digraph G {A -> B; A -> C; A -> D} <graphviz> digraph G {A -> B; A -> C; A -> D} </graphviz>

digraph G {graph[rankdir=LR]; A -> B; A -> C; A -> D} <graphviz> digraph G {graph[rankdir=LR]; A -> B; A -> C; A -> D} </graphviz>

digraph G {
graph[rankdir=LR];
A [style=filled,color="#999999"];
B [shape=box];
C [fillcolor=yellow, style="rounded,filled", shape=box];
D [fillcolor=yellow, style="rounded,filled", shape=diamond];
E [shape=record, label="{ a | b | c }"];
F [shape=circle]; 
A->B; A->C; B->C; B->D; B->E; D->E; E->F; C->F;}

<graphviz> digraph G { graph[rankdir=LR]; A [style=filled,color="#999999"]; B [shape=box]; C [fillcolor=yellow, style="rounded,filled", shape=box]; D [fillcolor=yellow, style="rounded,filled", shape=diamond]; E [shape=record, label="{ a | b | c }"]; F [shape=circle]; A->B; A->C; B->C; B->D; B->E; D->E; E->F; C->F;} </graphviz>