The Athena environment is a very complex entity. Any attempt to completely define it is likely to be full of gaps. For example, one might forget the network services that must be available, or the knowledge that must exist in support groups for customers to get the kind of service to which they have become accustomed.
However, the work done in Layered Athena makes it possible to answer the question, ``What software makes a Unix workstation into an Athena workstation?'' A similar question is, ``What development work needs to be done for an Athena port?''
These questions become very important when we begin to look into new models for the Athena computing environment. A picture of the components of this environment make it easy to point out how a new model is and isn't different from our present model, thus making it easier to estimate how much more or less effort will be involved in the ``new model'' port.
An Athena port has three main software components:
Layered Athena deals primarily with the anatomy of the system packs, but the other components are described here for completeness. Forgetting the about installation process is a grave error if one wishes to put a new Athena platform in public clusters. Forgetting locker software shows that one is out of touch with the expectations of the Athena user community.