Effective support of these applications in
such an environment suggests the concept of treating the entire
collection of resources as a metacomputer that would present a single,
seamless interface to the user. Applications would be executed on a
virtual machine (whose binding to physical resources may vary
dynamically during the lifetime of any particular job) allocated
according to specified performance and assurance constraints. ...
Potential advantages of the metacomputer include not only its
tremendous aggregate performance but also the ability to adapt during
crises. ... It will be extraordinarily difficult for users to exploit
it directly. To minimize this barrier, a shared memory programming
model accessible from familiar programming languages needs to be
--DRPA BAA, 1996.