We developed a methodology to evaluate interactive performance of GUI and multimedia applications, and we conducted a thorough quantitative analysis on the Sun Ray implementation of such a system. We demonstrated that commodity ethernet provides an interactive experience that is indistinguishable from traditional desktops, even for highly interactive 3D video games. In fact, most applications run well over DSL or cable modems to the home. To support computational service on a globally distributed set of machines, we restructured operating systems using a new abstraction called a compute capsule. Capsules provide a private, virtualized, machine-independent interface to system resources, and they encapsulate all the state of a user's active computing session.
Capsules can migrate between machines or reside off-line in stable storage.
Hosts in the system merely serve as caches for active computations. Capsules are isolated for privacy, customizable for flexibility, and schedulable for performance. We have demonstrated that it is feasible to extend COTS operating systems with this abstraction, and our prototype can suspend and resume complete login sessions running standard batch, GUI, and multimedia applications. The applications resume as if nothing happened. Publications Supporting Ubiquitous Computing with Stateless Consoles and Computation Caches B. K. Schmidt Ph.D. Thesis, Computer Science Department, Stanford University, August 2000.