Ooo is this some backstory to why your plugins are so unbeatable? :P

I've asked around, and code is instantly copyrighted material as soon as it's written (Well that's the law here in australia)...

Licences come in when you want to distrubute the code, and it ensures that people just can't take it and then break the agreement in your licence, eg. someone taking b2evolution and then calling it wordpress360 and selling it for 10$ a pop.

So seeing as they have actually released the code, without a licence, you could do whatever you dam well please with it. But i think they can still take you to court if they wanted, but you just show those messages that you had with the co-author and it will work out.

I dunno, i'm probably just a little less confused as you on how this whole open source thing works. But pretty dam sure you have nothing to worry about.

Francois and Blueyed would have the best knowledge about this stuff I would imagine.

Given the fact that you have made all reasonable contact and received a positive "permission" I would go ahead and simple give an attribution plus a short disclaimer note about the "other" developer/contributorthat cannot be contacted.

Your arse is covered as you have done all you reasonably could be expected to.

Cool then, as that's sort of where I was at. I mean like the code is out there to see and it doesn't say anything special and it's not like I had to work to find it - it's linked on a blog post. And I have tried. And I'll of course give credit.

So look forward to visiglyphs for b2evolution in the morning. What's a visiglyph you might ask? Google the term and you'll see, or dig this: your commenter's IP is salted and hashed and salted and hashed, then the result is used to make a quilt-like 9-block .png file. In my hack-mod thing I then prepend the comment with the image tag and a class to flow the text around it.

Think of it as an IP-driven avatar.

Yeah. Cool. Especially for those of you who get comments because, like for example, you post about stuff people like to read about.

Interesting plugin and v.cool hackage. I saw it in action on your site and ... it looks like a 3rd party is now involved in the "credits"?

Personally, regarding your concern and original post, I think that:

1/ The fact that yer using it for open-source and giving it away would convince ANY legal intentity that yer not anybody to worry about,

2/ If you document (just don't delete ... nothing formal) any correspondence that shows you TRIED ... no one could ever really have a claim

and

3/ That it's better to beg for forgiveness than ask for permission! :D

YER GOOD TO GO !! :D

As I understand it, one of the big advantages of the [url=http://en.wikipedia.org/wiki/GNU_General_Public_License]GPL[/url] is that when you release something under it, anyone who makes a derivative work must also release their code under the GPL and make it freely available. If the original code author had done GPL instead of public domain, then you would have known for sure that you can take any derivative work and make a further derivative work.

There are other open source licenses which don't require that derivative works also be open source. That's how Apple was able to take the BSD operating system and make a commercial version of it called OS X. The [url=http://en.wikipedia.org/wiki/BSD_licenses]BSD license[/url] is more like public domain.

b2evolution is mostly GPL. There are some dual-licensed parts, too. That's why you can fork the code and make your own project from it, but it would have to be free and open source, too. GPL guarantees that any innovation built on GPL code will be shared with the community. That's good most of the time, but it also means that some commercial companies will choose not to use GPL code because they don't want to share.

Francois and Daniel know loads about this and can probably correct me on a few things.

I do agree with everyone else who's saying that you'll be fine. The worst you would get is a cease and desist letter asking you to take down your code. I doubt that ever happens. But this is a good reminder. I've been thinking that plugin authors (myself included) should pick licenses for their work and put in the appropriate notices.