1. An apparatus providing a plurality of computing sources of functionality, each computing source of functionality presenting a service and existing in a computing environment of the apparatus, in a computing environment in network communication with the apparatus, or in any combinations thereof, the apparatus comprising: a computer processor; and a non-transitory computer readable storage medium which stores instructions, which when executed by the computer processor, cause the computer processor to execute: dynamically discover one or more semantic service descriptions (SSDs) as known services through a plurality of discovery mechanisms discovering the SSDs, an SSD including a semantic description of the service and a semantic description of a parameter of the service, according to a computer interpretable language, and as a service grounding, mapping information between the computer interpretable language expressing the SSD and an interface, including an interface parameter, of the service; support dynamic composition of a task composed of a plurality of the discovered known services based upon a task composer selection of a plurality of the discovered known services; and dynamically output a specification of association of user interface (UI) objects, user interface (UI) events and user interface (UI) display screens to a selected composed tasks responsive to selection of a UI object and association of the selected UI object with a selected UI event to a selected UI display screen from selectable lists of one or more UI objects, UI events and UI display screens and selection of a composed task from among composed task candidates identified based upon input/output of a composed task and input/output of the selected UI object associated with the UI event to the UI display screen, thereby the selected composed task is executable upon displaying of the selected UI display screen and upon action on the selected UI event associated with the selected UI object displayed in the displayed selected UI display screen, wherein a UI object corresponds to an SSD as a discovered known service included in the selected composed task, wherein the specification of association of the UI objects, the UI events and the UI display screens to the selected composed tasks comprises generating a matrix of the selected UI object, the selected UI display screen for the selected UI object, the selected UI event for the selected UI object and the selected composed task.