To build a distributed operating system the microkernel
    approach is the most popular. To build an adaptable operating
    system a minimal microkernel is preferred. But for an adaptable
    and flexible distributed operating system the previous approaches
    are not enough because they create an artificial barrier to OS
    distribution and harm system transparency and adaptability.
  
  
    This paper describes the implementation of the Off
    system, where the microkernel itself and its abstractions
    are both distributed and adaptable.  We show how the system
    interface is close to the hardware but not restricted to a
    local node.  The whole network is exported and multiplexed
    hardware in contrast to what is done by today microkernel in
    ``distributed'' OSes.  In this way the artificial view of nodes as
    isolated entities can be eliminated and the system can maintain
    both adaptability and other good properties for system
    distribution as inherent features.