"The server would work on the text of the sources, such as docstrings found in the Anarki source code. That way even if someone pushed something malicious to Anarki then we wouldn't have a security problem (either on the server or in the reader's browser)."
If it ever got to the point where actually eval'ing the code were necessary/desirable, you could do so in a safe namespace in PyArc (hint hint).
