[plt-scheme] How best to create a "sandbox" environment?

>

Hi,

> What would be an approach to preparing a sandbox that disallowed IO?
>

Check out this entry in the Scheme cookbook:

http://schemecookbook.org/Cookbook/DynamicUntrustedEval

AFAIK nobody has used this in a public service and the security  
features of MzScheme haven't been under intensive attack so far, so I  
wouldn't depend my life on the security of it.

Greetings,

Erich