Providing modern numerical techniques to large-scale applications is an increasing problem being faced by developers of numerical software. A number of research groups have found component-based design to be effective in managing this complexity. Fueled by the DOE2000 initiative, which aims at promoting more interaction among software efforts, an interest has grown in coordinating such tools. Since the promise of component technology is to interoperate easily with tools that provide similar functionality, the CCA working group represents a next step in exploring this direction. We will give examples of some tools currently in use and under development by members of the CCA working group, and we will discuss issues and trade-offs in performance and reliability for numerical components.