A nominal type framework can be configured to efficiently correlate different nominal types together based on a minimum set of common type shapes or structures. In one implementation, a developer identifies a number of different nominal types of interest (source types), and identifies the minimum set of common type shapes to be accessed by an application program. The minimum set of common type shapes can then be used to create an intermediate type (target type) to which each of the other different source types can be mapped. For example, one or more proxies can be created that map shapes of the one or more source types to corresponding shapes of the created target type. The application program created by the developer, in turn, can access, operate on, or otherwise use the mapped data of each different source type through a single target type.