The major evolution in the VMS application software has been the partitioning of the software into a hierarchy of sharable images . These are dynamically linked when a SCP is started and thus can be individually modified and released, subject to their defined dependencies. The EPICs display tools now allow us to easily build graphic displays which under to old SLC system required a separate program for each display. However, we still link an entire image which is downloaded and debugged in situ like always. The operating environment of the Control System Hardware includes the entire scope of the machine.
Central computers can reside in a well controlled air-conditioned environment.
Some computational power however must be distributed throughout the machine, spanning a distance of many miles and in more computer hostile locations. The environment for the Control System Software is one of constant change and enhancement by a substantial team of programmers and Physicists. It must be upgradable and maintainable over a long period of time. I guess it's a truism that no matter what the given performance of a system, more will always be desired. No Home-Grown Network.