The talk given at the FOSDEM conference in 2023 was about open source software development and how to grow open source adoption. The speaker emphasized the importance of building a kick-ass open source project, understanding the target audience, and making the software easy to use. They discussed different metrics to track open source usage and adoption, including awareness, usage, conversion, customers, and retention. The speaker also highlighted the role of the community in driving open source adoption and discussed different strategies to foster a strong community. Overall, the talk provided insights and guidance on how to successfully grow open source adoption.