In order to build complex, large-scale, dependable systems it is necessary to use a development environment with an integrated set of capabilities that supports editing and formalization of large sets of requirements. In this paper, we introduce a new environment, called “Integrare”, which supports designers and developers in building dependable, component-based systems using a new behaviororiented design method. This method has advantages in terms of its abilities to manage complexity, find defects and make checks of dependability. The environment integrates and unifies several tools that support multiple phases of the design process, allowing them to interact and exchange information, as well as providing efficient editing capabilities. It incorporates a Requirements Translation Assistant that can help formalize individual natural language functional requirements as Behavior Trees. These trees can be composed to create an integrated tree-like view of all the formalized requireme...