One of the elements of E/E that has been around for awhile now is AUTOSAR, or Automotive Open Systems Architecture. It is a standard that concentrates on engine control units. The OSEK OS, an ISO standard (ISO 17356-3) is the foundation for the specification of the operating system; it specifies the interfaces to the task-oriented functions of the OS. AUTOSAR also specifies an AUTOSAR Runtime Environment that provides middleware functions for the applications. A Microcontroller Abstraction Layer (MCAL) abstracts the microcontroller's hardware to provide a standard interface for functions such as I/O and flash. AUTOSAR also includes a methodology for configuring an AUTOSAR-compliant system from its components.