Different graph engines are implemented in each directory.
Each engine has a JS interface so they can all plug into the same data source
which comes from graph.js.
Open the index.html file in each directory.
You will need to view these files through a web server otherwise the browser will block you from loading the graph files due to cross-site-scripting.
Open your browser console, timings will be written here.
To generate a JSON file from a .dot file (as output by cylc graph) you can do something along the lines of this:
echo [ > graph.json; grep '\->' graph.dot | sed 's/\[.*//; s/ \->/,/g; s/^\t*//; s/^/\[/; s/ *$//; s/$/\],/' >> graph.json; echo ] >> graph.json
# remove final comma