I'm a non-Wine developer but I've taken an interest in this debate since I could possibly work on it in a commerical way and would prefer to see it truly open for everyone.
Rather than debate GPL vs BSD license, first get a consensus on what the *goal* and purpose of a license would be. E.g., attracting commercial development, maintaining control, philosophical reasons, etc.
Forget the philosophical and semantic arguments over "free", "open", etc. if I was a member of the Wine group I would want to maintain control over it. Using a *GPL style license would seem to insure more control over the code, as opposed to a commercial third-party taking control and benefit from the work already done.
From what I've seen Wine is such a huge undertaking that there are still
large areas that are incomplete or in need of much improvement. That seems different than some of the more well known examples of BSD licensed projects that's cited as examples of doing fine with a BSD license. In other words, let's say Wine is "half-way" done (or more). Who would you want to complete it? Yourselves or companies that would not contribute their code back to the community?
Didn't the fragmentation of Unix come from several companies using a BSD or proprietary licensed codebase? That fragmentation hasn't been a problem with Linux since it was GPL from day one. So Linus and the community are still the ones with control and ownership of Linux, not any single company.
If several different *competing* companies take off with the existing Wine code it will without doubt fragment. In fact it seems like it already has. If there are several different proprietary Wines floating around without improvements and code available then the Wine group's leverage of being the "official source" would diminish in a way that Linux, GNU, KDE, etc have manged to maintain with the *GPL license.
jasonp San Diego, CA