I am working on a open-source project which is backed by an organization. Organization pays a team to make this open-source project. This project will be licensed with GPLv3.

We are debating on having a CLA for contributors. Do you think mandating a CLA will reduce the number of contributors? I have observed that people have no issues in signing a CLA when the project is really popular.

So do you think CLA will create a resistance to contribute?

  • 2
    Yes it does. Getting the CLA for contributing to GCC took me several months of boring and unpleasant internal lobbying (because the CLA has to be signed by a legal representative and I'm working in a large organization). And people have pain to get CLA signed (but they won't tell you). Aug 22, 2014 at 6:23
  • @BasileStarynkevitch But was that mainly because GCC guys take too long for process? Aug 22, 2014 at 6:28
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    No, it is because the CLA document is harsh (and lawyers want it to be so; ...). The pain was in my organization. If possible, avoid CLA. Aug 22, 2014 at 6:40
  • BTW, you should have named the open-source project which you are involved in. Aug 22, 2014 at 6:49

3 Answers 3


Yes, a CLA will create resistance. It's meant to do that.

The CLA will give your organization more posibilities with the source like, license the source commercially or make their own non-opensource products.

But it's always a tradeoff: you lose potential contributors that would have contributed without a CLA.

If that's worth it, is up to you and your organization. But either way you better choose from the start. Because if you want to add a CLA later you have to go back to all previous contributors and have them also sign it.


A CLA does create a huge resistance for contributing. It requires the potential contributor -often a software developer- to lobby the lawyers and managers of his organization (which may means months of painful, boring, unpleasant, internal lobbying) and to get a legal document signed by official representatives of his organization (in a large corporation, it is difficult). That contributor won't make the effort for an unknown free software (he/she might make that painful effort for a very popular software).

CLA are probably easier to accept in very small organizations like small start-ups or SMEs -because the developer can just go directly ask his boss = the SME owner or manager-, but people working in them are less likely to contribute to an external free software project.

It also remove the possibility of small contributions (someone sending you a few dozen lines of patches won't bother to get the CLA signed, and if the CLA is necessary to submit the patch, he won't even start working on that small patch), and this is how you get initial contributors.

So as a software developer and free software friend, I would tell you to avoid CLAs.

Of course, the lawyers of your organization will tell you the opposite (because lawyers also need to prove themselves useful, and because they can find horror stories, or because they think of relicensing the free software....).

BTW, lack of a formal CLA procedure is perhaps one of the reasons making github so successful.

I believe you first should make your free software popular and successful and attract small contributors; for that you need to avoid CLA.

In case it is not clear, I am advising not have any CLA at all, not adding some CLA later.

  • 1
    "I believe you first should make your free software popular and successful and attract small contributors; for that you need to avoid CLA." By the time your software becomes popular and your project has a dozen contributors, your project already will have so many people with their copyright rights on the source that making a CLA then will not work. Have one from the start or not.
    – Pieter B
    Aug 22, 2014 at 7:04
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    CLAs are not just to keep the lawyers busy. It is primarily a means for the organization behind a project to keep their options open with regard to license modifications. Aug 22, 2014 at 7:32
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    This is Extremely bad advice. There may be reasons for or against a CLA, but starting without one and then adding one later is one of the worst paths you can take.
    – Pieter B
    Aug 22, 2014 at 8:00

As a hobbyist open source contributor I would never contribute for free to a project which makes me sign a CLA. When I contribute open source code in my free-time, I do so because I want to help the greater good. I don't want my voluntary contribution to get relicensed under a proprietary license later. Lack of a CLA guarantees to me that my work will stay open source.

I would, however, willingly sign a CLA when I get paid for my work.

  • 4
    "Lack of a CLA guarantees to me that my work will stay open source." CLA's can provide that too.
    – Pieter B
    Aug 22, 2014 at 9:53

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