A language and system for composing autonomous, heterogeneous and distributed megamodules

New levels of software composition become possible through advances in distributed communication services. We focus on the composition of megamodules, which are large distributed components or computation servers that are autonomously operated and maintained. The composition of megamodules offers various challenges. Megamodules are not necessarily all accessible by the same distribution protocol (such as CORBA, DCOM, RMI and DCE). Their concurrent nature and potentially long duration of service execution necessitates asynchronous invocation and collection of results. Novel needs and opportunities for optimization arise when composing megamodules. In order to meet these challenges, we have defined a purely compositional language called CHAIMS, and are now developing the architecture supporting this language. In this paper we describe CHAIMS and how it meets the challenges of composing megamodules