Metal matrix composites have been described as "the materials of the future and always will be". A current review of the status of these materials, however, shows that there have been notable technical and commercial successes suggesting that an application foothold has been gained. Following a brief historical summary, this paper will describe the aluminum metal matrix composites materials currently available, some of their key microstructural and property characteristics, and application examples. A key barrier to expanded application is the lack of publicly available knowledge on the secondary processing of aluminum MMCs, and a brief review of key aspects is given. Finally, a perspective on the research and development needs for the future is provided as well.