Modeling and simulation in systems biology aim to understand the dynamic behavior of living organisms, from the cellular level to populations. As knowledge in biology accumulates rapidly, modeling and simulation must address large-scale systems with complex control and potentially stochastic effects. Formal modeling approaches are therefore essential for the description, verification, and prediction of the behavior of such systems. The Biocomputing team develops languages and algorithms for the modeling and simulation of living systems, as well as associated static analysis methods. Our approach is based on formal methods and the semantics of programming languages.