The 2XS team works on operating systems and software that face strong technological constraints and must meet requirements in terms of security, reliability, and efficiency. The team’s research particularly focuses on defining new system architectures or new techniques and algorithms to enable the rapid design of reliable software, adapted to strong constraints in terms of security and efficiency. The skills implemented by the team to address these challenges range from co-designing software and hardware to the use of formal methods (with the help of the Coq tool) and the co-design of software and their proofs.