When I first got into open source, I published everything as GPL. It seemed only fair: I make my code freely available, but in exchange people who use it need to do the same. There is a major long-standing hole in the GPL, however, which is that it only applies to software that runs on your device.

For example, if my friends and I write some spiffy software to let people sing together over the internet, licensing under the GPL wouldn't prevent someone from making a copy with private server-side enhancements.

The FSF offers the AGPL (license text) to close this gap: it requires you to provide the source code even if you're only making the software available over a network. This restores the key freedom of copyleft, the right to the source for the software you're using.

With web and mobile apps, many things that previously ran on your local computer now run in the cloud. With virtual desktop services like Windows 365, this can extend even to programs that weren't originally conceived as running over a network. So I'm struggling to see a good case for the regular GPL: if you care about copyleft, the AGPL just seems better, closing an important loophole.

On the other hand, as I've thought more about this I've realized that copyleft isn't a priority for me. Yes, people releasing their changes back would be nice, but I care much more about people being able to use the software for anything they want. With Bucket Brigade Singing, Whistle Synth, and my other projects, if someone used my code to make a slick commercial project I'd see that as a good thing: now more people can try out these ideas. The open source versions will still exist, just as I released them, and can still be extended by people who want to work together in the open.