Compsys is an EPC (équipe-projet commune), i.e., a research project-team that is common to several institutions: Inria, Ecole normale supérieure de Lyon (ENS-Lyon), CNRS, and Université Claude Bernard of Lyon (UCB-Lyon). It is located at Ecole normale supérieure de Lyon and exists since January 2002 as part of the computer science laboratory (Laboratoire de l'Informatique du Parallélisme, Lip, UMR CNRS ENS-Lyon UCB-Lyon Inria 5668) and as an Inria pre-project. It became a full Inria project in January 2004. It has been evaluated by Inria in Spring 2007 and extended 4 more years. It has been evaluated by AERES in December 2010 and received the mark A+. It has been evaluated positively again by Inria in Spring 2012.

The goal of Compsys is to develop compilation techniques, more precisely code optimization techniques, for programming or designing embedded computing systems. So far, Compsys focused on both low-level (back-end) optimizations for embedded processors and high-level (front-end, mainly source-to-source) transformations for high-level synthesis of hardware accelerators. Recent activities also include a shift towards dynamic compilation and compilation for GPUs and multicores. The main characteristic of Compsys is its focus on combinatorial optimization problems (graph algorithms, linear programming, polyhedral optimizations) coming from code optimization problems (register allocation, memory optimization, scheduling, automatic generation of interfaces, etc.) and the validation of these techniques in the development of compilation tools.