There are many uses for a chemical relational database. Some of these have been mentioned in earlier chapters. In this chapter, three general types applications will be discussed. The purpose is not to present complete working applications, but to indicate important issues to consider when designing such applications. Sample schemas are proposed. The use within each application of the core functions described earlier is discussed. Each of these applications might be developed as a web application or a client application on a user's desktop. Any computer language might be used, although the ability to connect to a RDBMS is essential.