We can define a simple layered architecture for Web (NII) applications which are built in terms of multi-use services as shown in Figure 13. ``Multi-use'' extends the well known dual-use civilian-military interplay to a set of capabilities shared by many different applications. Note the Web is an excellent implementation technology for the COTS (customer off the shelf) choice used in many new defense software systems. There is no precise definition of services and their difference from applications, for services are essentially generic applications, and most applications are complex metaproblems built recursively from services and ``sub-applications'' [Fox:95c]. Table 2 maps services onto seven application areas.
Thus, there is a grey fuzzy line distinguishing services and applications. Five possible NII services include:
| Applications | WebTop Productivity |
Info VISiON |
Commerce/ Security |
Collab- oration |
Meta Computing |
|---|---|---|---|---|---|
| Society | X | X | X | X | |
| Education | X | X | X | ||
| Enterprise Systems | X | X | X | X | |
| Health Care | X | X | X | X | X |
| Command and Control/ Crisis Management |
X | X | X | X | X |
| Manufacturing | X | X | X | X | X |
| Collaboratory | X | X | X |
Here, we put base productivity tools including ``WebWord,'' ``WebLotus123,'' Web linkage to relationship databases, etc. Essentially, all applications use this service.
As described in Section 2.2, this includes base database storage, management, query, and dissemination of the full range of multimedia archives of the World's distributed digital libraries. Note delivery of results of a simulation--such as access on demand to a weather model--is included in this service.
Considering the two examples from Section 4, in manufacturing, InfoVISiON corresponds to delivery of data in a configuration controlled database. In command and control, this service allows commander to index and access videos of battle damage videos or real-time engagements.
This collection of services enables electronic commerce, including on-line banking and shopping. These services are also essential for the use of the WWW for processing and exchange of proprietary (manufacturing), and classified (military) data.
This includes desktop video conferencing, three-dimensional graphics MOOs, geographically distributed CAVEs leading to full televirtual interactions. Java-based client-server systems, such as Tango [Beca:97a] and Habanero [NCSA:97b] are very promising. The emerging VRML 2.0 standards will be very important in building virtual environments. As discussed earlier, a wide variety of other types of interactive information exchange is necessary. This underlies the concepts of collaboratories (virtual research groups or scientific laboratories), and the virtual company of the next century's agile manufacturing environment. In the more static mode, we see workflow and configuration control, which allows tightly integrated projects, such as those needed to build a complex system including an aircraft (see Section 4.4) or a large software module with a distributed team.
This service can be used to control remote medical and scientific instruments; search the world for information; simulate the weather expected in a military engagement, or link computers in different companies for a multi-disciplinary optimization of a new vehicle.
In several articles ([Beca:97a], [Bhatia:97a], [Fox:97a]), we have explored the use of Web software as the basis of the operating and programming environments of parallel processors. In the pyramid view of computing (Figure 12), this uses the philosophy of Figure 9 to extrapolate software from the base to the top of the pyramid. This implies Web hardware (the collection of clients from Figure 5) could provide the world's fastest computer while Web software will run the largest tightly coupled parallel computers.
Figure 12: Integration of Large Scale Computing and Web Technologies
Some services listed above can be already prototyped in terms of today's Web technologies. For example, base WebTop or early Collaboration services are now becoming available. Some other services are still waiting for their pervasive enabling technologies, such as the physical infrastructure that will enable InfoVISiON or security that will enable Internet Commerce. Finally, the computationally extensive NII services, characterized above broadly as ``Metacomputing'' require a major extension of the whole Web paradigm, currently still focused on image and document services, but already gradually expanding towards computation and interactive simulation via technologies such as Java and VRML.