Appl.xml files provide well-defined descriptions of applications sufficient to generate basic implementations of them for several different computational infrastructures, such as HTTP container, Web container, or Web plus EJB container solutions. A desirable extension of this capability would be to compose the descriptions of a pair of simple applications to form a more complex application that combines the properties and capabilities of the two constituents. This capability would support a notion of very light-weight libraries of components that could be combined in well-defined but arbitrary ways to produce new, more extensive applications. Or, more accurately, descriptions of new, more extensive applications whose implementations could then be automatically generated.
To guide this work and to enable us to reason more formally about this notion of composing applications, we are attempting to develop a formal, abstract Algebra of Applications. References are provided below to definitions of the components from which we will try to build an algebra and our efforts to actually build that structure.
Application Algebraic Components