The number of software artefacts is growing at an astonishing speed, with Free Software components reused almost everywhere. This makes it every day more necessary to use tools to select and install software components in a coherent way. These tools, known as package managers, are complex pieces of software that pop up in all software ecosystems, every time developed differently, and yet every time sharing the same common core concepts. The talk describes these basic concepts, surveys some complexity results, and presents a modular architecture that will benefit all future package managers.

√ Bio : Roberto Di Cosmo is Professor of Computer Science at University Paris Diderot, after teaching for almost a decade at Ecole Normale Superieure in Paris. His interests span functional programming, parallel and distributed

programming, the semantics of programming languages, type systems, rewriting and linear logic. More recently, he focused on new scientific problems posed by the general adoption of Free Software, with a particular focus on static analysis of large software collections, coordinating the Mancoosi european project (www.mancoosi.org).  He is the director of IRILL (www.irill.org)