Metacomputing environments are not homogeneous. In some environments, the scheduler has a great deal of information about submitted jobs. In other cases, it has very little. In some cases, jobs have real-time demands. In some cases, they do not.
Some systems can migrate jobs without interrupting their execution.
The Java Market prototype is a metacomputer built atop Java and web technologies, able to integrate any consenting Internet-connected machine. The Frugal System transforms any Jini network into a metacomputer.