Geoffrey De Smet, creator of the OSS operations and scheduling tool OptaPlanner, describes his journey from building OptaPlanner as a project within RedHat to launching a COSS startup in order to rescue the project from cancellation. He talks about the highs, the lows, and the challenges and opportunities of building a sustainable COSS revenue model:

I had to build a product company. One that offers a subscription on top of the open source project. With a strong value proposition. Support alone wasn’t enough, so I decided to go for the open core business model: keep developing the open source solver, but sell proprietary services on top of it. 

That company became Timefold, which has raised €6,000,000 from top European VCs.