Re:Cedega Mashing (Score 2, Informative)

That's not really true - Cedega discloses their source code for some parts (e.g. their direct3D code), but the license used is not at all an Open Source (or Free Software) license. But ignoring that, some essential parts (like the copy protection implementation) are not provided except in binary form. To be fair, their agreement with the copy protection software company probably doesn't allow source disclosure of those parts.

Crossover Office does have provide the code used in their version of Wine: have a look at http://www.codeweavers.com/products/source/