Graphviz: easy graph visualization

This tool has been around for a while, but I still like how useful it is, so I thought I'd write a blog entry about it: Graphviz translates simple textual representation of graphs into diagrams. Visually, this covers everything where shapes are connected by lines (be it with or without arrows), which is quite a lot.
Example: The definition
digraph G {
    TODO -> "Buy food" ;
    TODO -> "Send out invites" ;
is displayed by Graphviz as:
  • The definition (and input of Graphviz) is just a text file which can be easily created by a program.
  • The GUI version of Graphviz watches files so the diagram will be updated automatically every time the text file changes.
  • Graphviz can export its visualizations in many formats (jpg, PDF, SVG, ...).
  • More examples: Graphviz Gallery, UML Diagrams Using Graphviz Dot.
  • Download (be sure to use one of the “Executable Packages from AT&T”).
Now, my only wish would be a pure JavaScript of Graphviz. All the Graphviz solutions that I’m aware of depend on a server-side native dot binary to do the graph layout.