It looks good to me (but I'm not a native English speaker :)).

I think this tutorial should be on the website. Would you mind converting it? If yes, some information is available here: http://www.macruby.org/documentation/website-contributions.html

Laurent


Done! :-) 

Commit : http://github.com/robgleeson/macruby_website/commit/f2551217962a938a83f1063af396f09b27879ac3
File       : http://github.com/robgleeson/macruby_website/blob/Sandbox_class_tutorial/content/documentation/the-sandbox-class.txt


Rob