Scripting Grafana dashboards

One day I came across Grafana and found it very attractive.
It's great usability and responsive design have quickly made it my favorite.
Templated dashboards feature is very handy.
But real power comes with scripted dashboards. It is possible to do async calls to external controller, get some JSON data, and construct dashboard object dynamically, based on the data received.

There were no good example or howto, though, so