How do you attract contributors to a new free software project?

I'm in the very early stages of a new personal project. It is irrelevant for this blog post what the new project actually is. Instead, I am thinking about the following question:

Do I want the project to be mainly for myself, and maybe a handful of others, or do I want to try to make it a more generally useful, possibly even a well-known, popular project? In other words, do I want to just solve a specific problem I have or try to solve it for a large group of people?

If it's a personal project, I'm all set. I can just start writing code. (In fact, I have.) If it's the latter, I'll need to attract contributions from others, and how do I do that?

I asked that question on Twitter and Mastodon and got several suggestions. This is a summary of those, with some editorialising from me.

  • The most important thing is probably that the project should aim for something that interests other people. The more people it interests, the easier it will be to attract contributors. This should be written up and displayed prominently: what does (or will) the software do and what can it e used for.

  • Having something that kind of works, and easy to improve, seems to also be key. An empty project is daunting to do anything with. Part of this is that the software the project is producing should be easy to install and get running. It doesn't have to be fully featured. It doesn't even have to be alpha level quality. It needs to do something.

    If the project is about producing a spell checker, say, and it doesn't even try to read an input file, it's probably too early for anyone else to contribute. A spell checker that lists every word in the input file as badly spelt is probably more attractive to contribute to.

  • It helps to document where a new contributor should start, and how they would submit their contribution. A list of easy things to work on may also help. Having a roadmap of near future developent steps and a long-term vision will make things easier. Having an architectural document to explain how the system hangs together will help.

  • A welcoming, constructive atmosphere helps. People should get quick feedback to questions, issues, patches, in order to build momentum. Make it fun for people to contibute, and they'll contribute more.

  • A public source code repository, and a public ticketing system, and public discussion forums (mailing lists, web forums, IRC channels, etc) will help.

  • Share the power in the project. Give others the power to make decisions, or merge things from other contributors. Having a clear, functioning governance structure from the start helps.

I don't know if these things are all correct, or that they're enough to grow a successful, popular project.

Karl Foger'l seminal book Producing Open Source Software should also be mentioned.