Abstract. Implementations of computer systems comprise many layers and employ a variety of programming languages. Building such systems requires support of an often complex, accompanying tool chain.The Verisoft project deals with the formal pervasive verification of computer systems. Making use of appropriate formal specification and proof tools, this task requires (i) specifying the layers and languages used in the implementation, (ii) specifying and verifying the algorithms employed by the tool chain (or, alternatively, validating their actual output), and (iii) proving simulation statements between layers, arguing about the programs residing at the different layers. Combining the simulation statements for all layers should allow to transfer correctness results for top-layer programs to their bottom-layer representation; in this manner, a verified stack can be built.Maintaining all formal artifacts, the actual system implementation, and the (verification) tool chain is a challenging task. We call sets of tools that help addressing this task system verification environments. In this paper, we describe the structure, contents, and architecture of the system verification environment used in the Verisoft project.