The project ArchiTOOL aims at inventing, prototyping, and evaluating an immersive and intelligent virtual environment for architecting complex technological systems. Instead of using domain-specific engineering software, the immersive and interactive environment will provide the architect with the modelling capabilities required to define the various views (operational, specification, functional, behavioural, structural, logic, safety, etc.) of a system architecture in a single virtual space before exporting each viewpoint in a standardised format that will enable domain-experts to continue with a detailed design. Moreover, the immersive environment will include a cognitive agent to support the system architect with intelligent capabilities: models verification, context-aware recommendation of rules, identification and automation of modelling routines...