At first I thought the GNU FDL was okay. And I tend to cut RMS a lot of slack. But the more I think about it, the less I like it.
One principle of a proper free license is that it doesn't allow the thing it is protecting to be poisoned. In the case of the GNU FDL, despite the laudatory goals, it basically makes a deal: here's the text or code or whatever, and in exchange you have to give the author a soapbox. Some advertising space, really. New and contributing authors can add their own little soapbox speeches, their own little bon mots. There's nothing to prevent a manual from becoming rapidly covered with a hundred little impassioned pleas. Once there are two, adding a third is irresistible. And each one would be considered using a "marginal cost/benefit" analysis. Each one would be little extra cost, so the benefit of added meat for the document itself that comes along with each extra invariant blurb could actually be pretty small. This would be a bad result. It is not a road we should start down. Don't get me wrong - I don't have a problem with RMS's impassioned pleas for free software sitting on *my* machine. If he asked me, as a personal favor, to let him put up a collection of his writings on each machine in my lab, and make them all web servers, and put an FSF billboard on the sign on the top of my car, and some FSF decals on my luggage, I would. As a personal favor. Because I'm so grateful to him for the wonderful things he's done. But I do have a problem with forcing people who just want some documentation to keep unrelated "invariant text" around. Especially since it wouldn't have to be RMS's, it could end up also having some advertising copy from IBM, and some more adds from a book publisher, and a sad story from a native american about how his people were screwed a hundred years ago, and another little bit about the horrors of Waco, and something from the ACLU, and then an add for UNICEF, and some gun nut screed of Eric Raymond's added by one of his disciples. This is a very bad direction to go. At heart, the FDL allows an add-space-for-usage deal. This is roughly equivalent to licenses we've rejected, like link-on-your-web-page-ware. I really hope the GNU project comes to its senses on this one. (The technical argument - that the line between code & documentation can be blurry and therefore the documentation should have something GNU GPL compatible - also seems rather strong.)
