However I have a feeling that there is a sufficient body of GPL/LGPL code out there that people will just modify that.
Since a lot of OSS code is contributed by companies, they don't really have any incentive to contribute to an AGPL project (in most cases).
Warning: If any of the following is incorrect, I would really appreciate someone correcting me. I use the AGPL, and if I'm incorrect, I would like to know.
You never have to push your changes back upstream. I'm not aware of any license that requires you to submit your changes back to the original author. You just have to make it accessible to your users.
Just like the GPL, you can run AGPL code on a private network and not have to publicly release the source code. It's when the network is public that you have to make the source code available.
If I visit your website, enter in some data, a script/lib licensed under the AGPL does something with it and returns a result. You must release the source code of "everything that it touches".
If you have a business and on the company Intranet you have the same script, while the employees (users) are entitled to have a copy of the source code, you are not required to publicly release the source code. Of course, other laws prevent those employees from also releasing the source code to the public and AFAIK they "trump" copyright laws eg.NDA.
Since a lot of OSS code is contributed by companies, they don't really have any incentive to contribute to an AGPL project (in most cases).
I don't know, companies contribute to GPL licensed code even when they don't explicitly have to. Just off the top of my head, tarsnap comes to mind, he contributes back to libarchive even though he is not required to do so.
That doesn't mean I don't see your point though. You could just as easily suggest that if libarchive was licensed under the AGPL that tarsnap wouldn't have used it in the first place due to the fact he would have to release the source of the entire stack.
So I think you argument should really be "Why should companies even use software under the AGPL" not "Why should they contribute back". I don't really have an answer for that, but the same argument was made about the GPL and companies still use GPL licensed software. I'm sure if you asked rms that question he would say something about not caring about companies that want to restrict his freedom....
As for requirements to push back changes - of course not. The only license I know of that does something similar is the SMF - Simple Machines Forum - license[1]. Yuck.
The argument between GPL and AGPL is similar to the one between BSD (or similar) and GPL on the desktop. My own position is that yes, I expect humans to be inherently good, kind and sharing souls and thus the BSD should be the license of choice. However, I have to be pragmatic and say - if we all assume that humans act like that, what's the harm in writing that down into the license? All it can do is make it hard for people who don't want to give back. So in my eyes, that's an important feature to have.
Yeah, sorry. I think that was a poor choice of words on my part.
For instance, if you have a website that uses AGPL code to produce an HTML page and non-AGPL code to provide a PDF from that HTML page, the two packages would indeed touch, but there would be no obligation to release the non-AGPL code, just the AGPL code.
Interesting, in your example, if your application calls the AGPL code that is used to generate the HTML wouldn't your application also have to be released under the AGPL? Or do you only have to make available the AGPL "HTML generation library" and the changes you have made to it (if any)?
I thought that it had already been established that if you use a library under the GPL any code that uses/calls that library must be released under the GPL. The only reason companies can use GPL code server side is because it is not run on the user's machine (technically not "releasing it"), which was the basis for the creation of the AGPL, to "fix" this "loophole".
edit:
Thanks skore, yeah I think your example still stands. Specifically, in the wikipedia article you linked this part:
By contrast, pipes, sockets and command-line arguments are communication mechanisms normally used between two separate programs.
To continue the original example, if your program just runs the HTML generation program and supplies user data via a command line argument then it need not be released under a compatible license. But on the other hand if you were to "copy and paste" the functions from that program into yours, it would need to be licensed under a compatible license.
The AGPL basically establishes the same concept on the internet that the GPL has established on the desktop.
I see, interesting idea unfortunately I really can't see it taking off, most companies would just prefer to work internally and then release some bits of code as LGPL/BSD when they are ready. What advantage could AGPL give the developer (assuming they are writing OSS for commercial rather than ideological reasons)?
The commercial advantage is that it levels the playing field: If I create a library that can be used for a website and release it as FOSS under a license that is not as restrictive as the AGPL, I basically create a disadvantage to my own business: Another company could use my code in a closed service and thus benefit from my work without giving me and their users the courtesy of benefiting from their work in return.
I write commercial GPL software and will, in my next refactor, license certain parts of the software as AGPL. An example would be a library that connects an invoicing system to an online payment processor (ie. creates a full checkout process for invoice X at amount Y). I have a lot of work invested in the code (basically 5 years of my life) and the better and more reusable I make it, the easier it is to just retool it for another application. I would naturally love to see websites utilize the code, even if it is just in a SaaS setting. But since it is my work, I have decided to set the rules and if people want to use it, I think it's fair to ask that they should promote the same liberties that they received from me.
