[davidroetzel]

One problem with dual-licensing though is that open source contribution becomes unnecessarily hard. Every contributor will have to sign a Contributor License Agreement, that at the very least allows you to dual-license their code. Many CLAs even have the contributor sign over her copyright to you.

Not everyone will be happy to sign something like that. And integrating a pull request on github suddenly becomes a tedious excercise in international copyright law :)

So dual-licensing gives you all the publicity-related and try-before-you-buy advantages of open source. But you will probably miss out on other great aspects, especially community-wise.

[logn]

It's prudent to have a CLA anyhow. Even if a whole project were AGPL, an employer of some contributor could claim ownership and IP theft.

And the right to fork a project also means the right to put conditions on accepting contributions.

And there are more advantages than publicity and free demo, namely that users have freedom to run the app themselves, find another service provider, find another project maintainer, etc. I'd see it as a far less risky situation than anything proprietary. Compared to Apache/BSD/MIT it's less risky in the sense that people aren't going to be introducing proprietary forks.

[tzs]

Another approach is to dispense with CLAs and copyright assignment, and let the community edition diverge from what you run for your paid service.

If you do that, you can't incorporate improvements from the community edition back into your code by simply copying them, but you can use them for inspiration to guide your parallel development for the paid version. That's more work than simple copying, but less work than developing new features from scratch.

[belorn]

This is a problem for all those 0.1% of FLOSS projects which actually get contributions. If yours are one of those, then donations or grants is something to look into in favor of dual-licenses.

[arethuza]

Could that be fixed by having a technical architecture that supported additional functionality by plugins? So the core product is dual licensed and contributions are done as plugins that can be licensed separately?