On Thu, 2004-02-26 at 12:39, Volker Dormeyer wrote:
if this is the case, the "public domain" category description on
http://www.gnu.org/philosophy/categories.html#PublicDomainSoftware
might be wrong, because it suggests that code without a copyright is public domain.
No, that description is correct, PD software isn't copyrighted. What I was saying was that software without a copyright notice may not be public domain: you don't *have* to put a notice on things you author, so if you wrote a piece of software tomorrow and didn't put a copyright notice on it, you would still have copyright on it and it wouldn't be public domain.
I'm interest in how someone can be certain, wether code without a copyright header is public domain or not? Does anybody know this?
You can't be certain, that's why it's recommended to put a notice on the software.
I'm fairly sure that in the UK you can't just mark a piece of software as "public domain", although taking that action would probably mean that you would find it extremely difficult to enforce your copyright at a later point. In the UK, moral rights are not attached to software either, whereas on the continent they are - and I'm told you cannot rescind those rights either, so again you wouldn't be able to say a piece of software is public domain.
Public domain is [usually] specifically those things that were copyrighted, but the copyright has now expired on (e.g., books in Project Gutenburg). It's highly likely, therefore, that the software isn't public domain in a true sense.
If the source code doesn't have a copyright notice, the best suggestion is to leave the source alone - unless you can establish whose it is, and get a license for it, you're probably just storing up trouble for later.
Cheers,
Alex.