[ArneBab]

“Most people suggest Apache”

Do you have metrics for that? I doubt your claim, given that the GPL is the most widely used license? GPL 2 and 3 and LGPL 2 and 3 alone are 40% of the licenses in the black duck stats: https://www.blackducksoftware.com/resources/data/top-20-open...

Share-Alike is the name which is easiest to understand. Copyleft is the historical name of the approach. Reciprocity is the concept.

[lighthawk]

Though it would be great if you could, don't use blackduck as the measuring stick. (Used to be Ohloh now) Blackduck is not a full view into the current state of open source and free software. I gave up on trying to keep my projects updated not long after the transition from Ohloh to Blackduck.

Apache is suggested as a free-software-compatible alternative to GPL v3 by RMS himself. In the past 15 years of contributing to open-source/free code projects, Apache is the longest standing license that over and over people have recommended. It is an intense license, but it covers the bases legally, whereas others do not. Still- I've used GPL, MIT, and BSD in the past- just learn about the pros and cons and choose what you think you should use, though.

[ArneBab]

If you have a better source, feel free to share it. This is a datapoint which strongly disagrees with your claim. It might be flawed, but that does not make it invalid. Do you have data which supports your claim?

That RMS says that you can use Apache if you don’t want copyleft does not support that it’s the most widely suggested. You can be sure that RMS will not suggest using Apache over GPL where GPL can be used.

There are less people who are opposed to Apache than there are people who are opposed to the GPL (or strong copyleft in general), but that does not mean that there are more people who would suggest using Apache than people who would suggest using the GPL.

Free Software proponents will say “I would suggest GPL, but Apache is still Free Software, so it’s OK”. This is not the same as suggesting to use Apache.

[lighthawk]

When I say "most people suggest Apache", I mean that for as long as I have been contributing to and developing with various open-source projects most people that I have talked with about licensing open-source or free software projects have suggested using the Apache license. I have also had someone tell me that he wouldn't use my project since it was MIT licensed, and suggest I start writing code under the Apache license if I didn't want to use GPL. Personally I have frequently not chosen to use the Apache license, but that is changing and actually I've been using GPL v3 in some recent work.

I suggested not using Blackduck's stats because they are incomplete. I know this because I used Ohloh for a few years and found that there were many projects that weren't listed there, and I did not have time to list all of mine there, and I have quite a few.

I do not have enough information to say for certain that GPL or any other license is the most well used license. If I had to guess, I'd say that there would be quite a large amount of code that is available online that has no stated license, so I'd think that would be the most common. After that, it could be "any version of GPL"- I don't know. Maybe Google with all of their resources and analytics would be best suited for determining a good estimate.