Le 3 Janvier 2006 10:45, Mathieu Bouchard a écrit :

Because with licences you can impose restrictions, even if it's only about the redistribution of the copyright notice. And also because licenses are more explicit than the "state of no copyright".

Laws and licenses are different things. Licenses are governed by international and national copyrights laws. That's why it's difficult to write a license with an international scope, translate it, and eventually test it in court. Also, the public domain is not a law. It's the law that is unclear about the fact that a work can go directly in the public domain, because copyright lawyers usually works to protect their clients investments.

It doesn't seem too difficult to publish a work in the public domain; since there's 566 projects in the public domain registered on Freshmeat: http://freshmeat.net/browse/197/

I don't think we can assume that a work is more or less in the public domain, where there is no conditions, not even redistributing the copyright notice. Even an extremely simple license like "no conditions" is technically expressing a condition.

Excerpt from http://www.gnu.org/philosophy/license-list.html#GPLCompatibleLicenses : "Being in the public domain is not a license--rather, it means the material is not copyrighted and no license is needed. Practically speaking, though, if a work is in the public domain, it might as well have an all-permissive non-copyleft free software license. Public domain status is compatible with the GNU GPL."