Three Layers
- The top
level is an intelligent graphical user interface for application use and
development.
- The intermediate software layer
consists of ``middleware'' for coordinating the upper and lower software
layers, for job compilation, execution, and monitoring, and for managing
the on-line documentation and help subsystems.
- The lowest level are software libraries and modules for
mathematical and scientific computation.
- The PSE will be designed
so that creating a new application-specific PSE affects only the upper and lower
software levels, leaving the middle layer unchanged.
http://www.netlib.org/utk/people/JackDongarra/