cally activated and able to make decisions independently. These agents will support users by performing routine tasks or submitting proposals when a decision needs to be made. They will also attend to any changes and respond to external events. Various digital assistants operate in a personalized agent system: Intelligent agents-Intelligent agents can draw their own conclusions and make decisions independently. User agents-User agents can execute orders, conduct negotiations, and communicate independently with other agents, acting as a substitute for the user. Cooperative agents-Cooperative agents perform a liaison function, ana- lyzing and interpreting the user's tasks and then deciding which functional agent would be appropriate. Functional agents-Functional agents contain the specific knowledge required to carry out a particular function. The Semantic Web A new, more intelligent Internet is a key requirement for communications between the various software agents. This new network will not only transport the signals, it will also understand their meanings. The semantic network, or the Semantic Web, is a current project of Tim Berners-Lee. The objectives of the Semantic Web include refined indexing xlviii Introduction and searching, as well as enhanced processing of structured information, where, for example, you can search by business documents versus scientific data, or where you can recognize the difference between an author and an entertainer. Also, the Semantic Web will be critical in the command and control of scientific instruments and the labeling of data. This is very important to data collection and archiving of all the data coming from the exploding population of sensors. The Semantic Web is a fascinating area of development, and I encourage you to learn more about it. The best starting point is the W3C Technology and Society domain website focusing on Semantic Web activity, at www.w3.org/2001/sw. Software agents must be capable of interworking as well as delegating subfunc- tions. As an example of th