See as an example, but not as complicated. http://pythontutor.com/ Could be as simple as a REPL with logging ## <bountysource-plugin> --- Want to back this issue? **[Post a bounty on it!](https://www.bountysource.com/issues/5524404-all-js-examples-should-run?utm_campaign=plugin&utm_content=tracker%2F130405&utm_medium=issues&utm_source=github)** We accept bounties via [Bountysource](https://www.bountysource.com/?utm_campaign=plugin&utm_content=tracker%2F130405&utm_medium=issues&utm_source=github). </bountysource-plugin>