The development of an embedded electronic architecture is a cooperative work involving an OEM and several Tier 1 suppliers . The result of this work is a complex distributed system, integrating several (heterogeneous) communication networks, and subject to stringent safety requirements. In this context, it is vital for the different stakeholders to master the complexity of the design of the embedded electronic architecture. One way to reach this goal is to use a modeling language capable of representing the system at all its design steps and common to all the actors involved in the design process. Ideally, this language must be based on a reference architecture defining the target of the design process. In the last 10 years, the European automotive industry has conducted several R&D projects to define such a modeling language and the accompanying reference architecture. For the modeling language, these efforts have led to the definition of several “Architecture Description Languages” (or ADL for short) such as AIL_Transport , or EAST-ADL and its successor EAST-ADL2. Concerning the reference architecture, it is defined today in the AUTOSAR (AUTomotive Open System Architecture) standards. This chapter focuses on the modeling language. It gives an overview of AUTOSAR, and the main principles of ADLs. Then, the EAST-ADL, an ADL dedicated to the automotive domain, is presented with a focus on the support it provides concerning the validation and verification (V&V) activities. This is illustrated with a case study.