GPL usage question

I'm having a hard time figuring out what I can do with gpl'd software, hopefully someone can help

Lets say (for the sake of the argument) I create a new forum script, and are planning to release it under the gpl. phpBB is also GPL software, does that mean I can use some of its code (say the BBCode module) in my site, and all I need to do is acknowledge them in the sourcecode?

Also
The phpBB forum requires a backlink to the main phpbb.com, does that mean the (complete new) software that I write must also include the link, even if I just use a few lines from their GPL'd code?

thanks.

 

There's no requirement to acknowledge them at all, only the requirement for your code to be licensed under the GPL too.
Of course, it's only polite to credit them if you're using their code.

They can't require a link back under the terms of the GPL, they merely suggest that you should link back to them. You needn't worry about giving them more PR than they already have

 

Well, if you use some of their code, you need to honor the terms of their license. That may mean that you have a choice of either paying them or releasing your code as source, depending.

Yes, I would say you may need to include the link if they require it, but it's hard to say because there are variations on the GPL. If the code you are borrowing seems too inconsequential to merit this, then you should probably be able to re-implement in your own code yourself (or with help).

You could always approach them directly and ask what their expectation is in cases like this.

 

As forkqueue said, you are free to use as much or as little GPL'd code in your work as you wish, as long as it is also GPL'd. No attribution (or linking) is required.

There are no variations of the GPL - the GPL is the GPL.

 

What about the lesser GPL, that's a variation, isn't it?

 

Well it's a seperate license. What I wanted to make clear was that if something says it's licensed under the GPL, it's licensed under the one-and-only GPL license. The LGPL is seperate and never referred to as the GPL.

 

Ah, I see. Thanks for clearing that up for me.