dot

Usage:
dot -Tpng -otest.png file.dot
twopi -Tpng -otest.png file.dot
circo -Tpng -otest.png file.dot

digraph test {
  element1 -gt; element2;
  "element 3" -> "element 4";
}

graph test {
  element1 -- element2;
  "element 3" -- "element 4";
}