The Nemesis system does not prescribe a scheduler per se; the Atropos scheduler is simply the one in common use. Other schedulers can be used where appropriate.
A alternative scheduler, known as the Jubilee scheduler, has been developed. It differs from the Atropos scheduler in that CPU resources are allocated to applications using a single system defined frequency. The period of this system wide frequency is known as a Jubilee and will typically be a few tens of milliseconds. The Jubilee scheduler has scheduling levels in a strict priority order, one for guaranteed CPU, the others for successively more speculative computations. Like Atropos, it has a mechanism for handing out slack time in the system. The use of priority is internal to the scheduler and not visible to client domains.
The fixed Jubilees remove the need for EDF scheduling and is particular suited to situations where the application load is well understood and where the a single Jubilee size can be chosen. Complete details can be found in [20].