D3 Graphviz GUI editor proof-of-concept
http://bl.ocks.org/magjac/b2bf6da945e725a605e0d077781457b2
d3-graphviz Basic Example
<!DOCTYPE html>
<meta charset="utf-8">
<body>
<script src="//d3js.org/d3.v5.min.js"></script>
<script src="https://unpkg.com/@hpcc-js/wasm@0.3.11/dist/index.min.js"></script>
<script src="https://unpkg.com/d3-graphviz@3.0.5/build/d3-graphviz.js"></script>
<div id="graph" style="text-align: center;"></div>
<script>
d3.select("#graph").graphviz()
.renderDot('digraph {a -> b}');
</script>