This is a quikie tool for directed acyclic graphs. It uses a simple 'A->B' notation to describe the graphs.

You can use the suffixes !, ', $ and ? to emphasize nodes. E.g. A$->B will cause A to be yellow.

Yes, that's Dot under the covers.

result graph
digraph G
{
    A->B;
    C[fillcolor="#ffee99" style="filled"];
    B->C;
    A->C;
}