I started playing with the free plan to get the idea of the service. It felt pretty good. There was a nice set of examples to start out. The editor seemed to work well. The workspace system seemed to work well. I can edit the code on the service and run it there.
In matter of few minutes I could select suitable code examples, view the source code and run then in the server (and get the output on web browser). Looks promising. One nice feature is that the system seems to remember where exactly my workspace was when session ends, and I can continue from it when I log in next time.