So, you want to create an open-source research software package — and not just for yourself or your group. You’d like people around the world to use it, and even contribute to it. How do you persuade them it’s worth their time?

Open-source projects rise and fall on trust. You may hope to build trust on technical merits: your algorithm is novel; your implementation fast; your tests thorough. All great, but not enough. Many technically excellent projects never break through because they neglect the social foundations of trust, which are laid long before a project matures.

And that's good news: you don’t need to be a top-tier programmer to build a successful open-source tool. Normal researchers do this all the time. What matters most is how you run the project, not how fancy the code is.

This talk distils lessons from years of building and maintaining scientific Python tools used by researchers worldwide. I’ll outline the practices that signal reliability and sustainability across a project’s lifecycle: defining and communicating your mission from the start; making a reasonable first release and following it up with consistency; and using open communication channels to embody your values and model healthy norms.

Throughout the talk, I’ll draw on examples from movement — a Python package I develop — and other tools built by the Research Software Engineering team I’m part of. That said, the lessons should be applicable to any free open-source project that aspires to attract and sustain a healthy community.

Takeaway: If you behave like a trustworthy project from the beginning, people will treat you like one, and help the project grow into what it promises to be.