As computational science has evolved, applications are being developed that focus on more complex problems. This often results in the use of a set of element applications, that focus on a relatively narrow aspect, to build composite applications that are more complex in scope. This often requires for the various codes that make up the composite application to be executed on several computers located on a heterogeneous network of computers. These codes may be stand-alone executables or they may be a library of functions (or objects for object-oriented languages). These codes are often created by multiple developers, so efficient code sharing and good portability are often important requirements. The use of software component technology is viewed as one approach for developing a software development environment, or framework, that supports the development of such applications.