In a nutshell, GPL v2 forces copyleft (giving back your code when using GPL code) only for distribution of the software as a floppy (or a CD, you get the picture). Distribution of software as a service was not covered (rightly so, the license was created in 1991...). However, since the world is quickly moving towards Sofware as a Services (SaaS), keeping the ASP loophole meant killing copyleft and - with that - the main reason for open source success ("forcing" people to contribute back).
Back then, I created HPL, the Honest Public License. To keep people that host SaaS honest with the open source principle (going "around" a license, because it did not specify something that happened some years later, does not sounds honest to me ;-)
My hope is that HPL one day will disappear because GPL v3 will supersede it. I plan to work hard to make it happen in the upcoming months.Well, HPL disappears today.
After months of hard work, AGPL v3 has been finalized by the Free Software Foundation. It is basically HPL, but upgraded to GPL v3 and even compatible with the Apache license. I could not have asked for a better result. Every thing I wanted is in the license. Fighting feels great when you win ;-)
Funambol is obviously the first commercial open source company to embrace AGPL v3. I am happy to announce that our upcoming GA release of Funambol 6.5 will be based on AGPL v3.
I believe AGPL will save open source. When the majority of software will run as a service, we'll look back at this moment and realize how important it was to have a license supporting this shift in computing. Without AGPL, open source would die for lack of copyleft.
If you are running an open source project and you believe it could be run as a service (think five years from now, not just today), please take a look at AGLP. Don't stop at GPL v3. If you chose GPL, it means you wanted people to contribute back to your project. If you let some people make changes to your code and not contribute them back, just because they distribute your code as a service, why did you choose GPL in the first place??
A few months back - after a couple of beers - I bet with Mark Radcliffe that in five years AGPL will outshine GPL. I have a feeling I will lose this one, because of lack of marketing power on my side, but - hey - I like to fight :-)
Just think about it, do not stop at GPL because others have done it. Your product might be distributed as a service one day (think Google Apps for a second). Choosing GPL over AGPL would be a terrible mistake that might dry up contribution to your open source project one day. A mistake that might eventually kill your project.
Don't be dumb, give it an A.