In this talk, I will reflect on experiences I have had navigating the landscape of open source scholarly software as projects age, and the way that shapes interaction in an ecosystem. I will also report some recent developments with the open source project yt, and how they both interact with the shifting needs and desires of community members and how they address the needs and desires of potential future community members. Many exciting buzzwords such as ‘Rust’ and ‘WebAssembly’ will be used.