title: Mathematica Module versus With or Block - Guideline, rule of thumb for usage?
body: <p>Leonid wrote in chapter iv of his book : &quot;... Module, Block and With. These constructs are explained in detail in Mathematica Book and Mathematica Help, so I will say just a few words about them here. ...&quot;</p>
  <p>From what I have read ( been able to find ) I am still in the dark. For packaged functions I ( simply ) use Module, because it works and I know the construct. It may not be the best choice though. It is not entirely clear to me ( from the documentation ) when, where or why to use With ( or Block ).</p>
  <h3>Question. Is there a rule of thumb / guideline on when to use Module, With or Block ( for functions in packages )? Are there limitations compared to Module? The docs say that With is faster. I want to be able to defend my =choice= for Module ( or another construct ).</h3>