This is a session combining the experience of several FOSS projects in their funding journey. Each will have 10 minutes to present, after which a Q&A session will happen.

The presenting FOSS projects will be:

• Mockoon is a popular open-source API tool, built and maintained from Luxembourg. In this talk, its creator shares the journey of growing a developer tool used by thousands, without external funding. Learn what worked (and didn't) in the pursuit of sustainability through sponsorships, community, and a cloud SaaS offering.

• DuckDB is the fastest growing data management tool to date. Meanwhile, DuckDB is Free and Open Source Software under the permissive MIT license. DuckDB's development began inside an academic instituted funded by grants. We then moved to a bootstrapped spin-off and have been running ever since. In my short talk, I will describe the meandering route and mental processes that lead us to choose this funding model, the things we do and why we do them, the things to avoid and why to avoid them.

• WeasyPrint is an open source Python library which transforms HTML/CSS into PDF, with the first commit dating back to April 2011. However we’ve only been making a living from it since 2020. We’ll present the evolution of our free software, how we transitioned from a project developed and used within a company to a product with paying clients, and discuss the different solutions we choose to earn money with free software.