Re: GFDL / CC by-sa compatibility

> The CC people already said that they are working on their next version of CC by-sa so that by-sa text can be licensed under the GNU FDL.

I sure hope this is made optional.  I don't want my free works altered and made non-free.

> IIRC Richard Stallman has already stated  to Jimbo that as far as he (RMS) was concerned the CC by-sa and the GFDL are compatible and text is interchangeable between the two.

They can't possibly be compatible.  A derivitive of something released under by-sa has to be released under by-sa.  That means you can't enforce invariant texts or cover texts, you can't require that "secondary sections" be about a particular subject matter, you can't force copies to be "transparent," you can't restrict titles, you can't limit the number of copies which can be distributed in a particular manner, and you can't require a "history" section.