You can only relicense it if you're the sole copyright owner. Otherwise you have to get approval from every single person who's ever contributed non-trivial cha

You can only relicense it if you're the sole copyright owner. Otherwise you have to get approval from every single person who's ever contributed non-trivial changes to the project. But the reverse isn't true; permissive licenses like 3-clause BSD are compatible with GPL, so if you default to a permissive GPL-compatible license, you can relicense under the GPL later if desired without having to get approval from all copyright owners (I'm assuming this is true of AGPL as well but I haven't investigated that particular point). Of course, someone else can fork it at that point and continue maintaining their fork under BSD, which is why you should think about the appropriate license to use before the project gets to a point where having the correct license is important. > What is your argument for "absolutely not" doing that and defaulting to 3-clause BSD when an author doesn't care about licensing? Copyleft licenses are actually fairly dangerous to developers. You have to basically treat any copyleft-licensed code as radioactive and keep it from tainting any other code on your computer. If you're the sole copyright owner it's not a big deal as you can relicense it, but once other people have contributed to the project, it becomes a problem. And on a related note, many developers (such as myself) are reluctant to contribute to GPL-licensed projects, and so using a permissive license is more likely to attract contributions.