14. A computer readable storage medium containing an executable program for building an automated assistant, where the program is configured to cause a processor to perform a method comprising: interfacing a service-oriented architecture comprising a plurality of services to an execution environment comprising an active ontology, wherein the active ontology models a domain and comprises a logical arrangement of a plurality of active processing elements, wherein each active processing element is configured to receive at least one fact relating to the modeled domain and to perform at least one action responsive to at least one received fact; and registering at least one of the plurality of services for use in the domain, by specifying at least one of: one or more active processing elements that the at least one of the plurality of services can accept; and one or more active processing elements that the at least one of the plurality of services cannot accept; wherein the active ontology filters requests for services to the at least one of the plurality of services in accordance with the one or more active processing elements specified by the at least one of the plurality of services.
14. A computer readable storage medium containing an executable program for building an automated assistant, where the program is configured to cause a processor to perform a method comprising: interfacing a service-oriented architecture comprising a plurality of services to an execution environment comprising an active ontology, wherein the active ontology models a domain and comprises a logical arrangement of a plurality of active processing elements, wherein each active processing element is configured to receive at least one fact relating to the modeled domain and to perform at least one action responsive to at least one received fact; and registering at least one of the plurality of services for use in the domain, by specifying at least one of: one or more active processing elements that the at least one of the plurality of services can accept; and one or more active processing elements that the at least one of the plurality of services cannot accept; wherein the active ontology filters requests for services to the at least one of the plurality of services in accordance with the one or more active processing elements specified by the at least one of the plurality of services. 15. The computer readable storage medium of claim 14 , wherein each active processing element represents at least one of: an object in the domain and a task to be accomplished in the domain.