Following the progress of the Modularity initiative and Factory 2.0developments in Fedora, it's about time we define what the next, modularoperating system should look like, focusing on the developer’s point of view. This first half of this talk will present the main concepts of Modularity,explaining in detail what modules are, how they get built, composed,distributed and kept updated once deployed on the target system. The second half of the talk will explore the idea of the so-calledGenerational Core, often also referred to as Base Runtime — a modular platformbase on top of which application modules can both be built and executed. Both these topics cover ongoing efforts and we don’t yet have definitiveanswers to all the questions. We’ll talk about what we learned in the pastyear, what problems we’re trying to solve and our plans for the future.