Patent attributes
A computer operating system with a map that relates API namespaces to components that implement an interface contracts for the namespaces. When an API namespace is to be used, a loader within the operating system uses the map to load components based on the map. An application can reference an API namespace in the same way as it references a dynamically linked library, but the implementation of the interface contract for the API namespace is not tied to a single file or to a static collection of files. The map may identify versions of the API namespace or values of runtime parameters that may be used to select appropriate files to implement an interface contract in scenarios that may depend on factors such as hardware in the execution environment, a version of the API namespace against which an application was developed or the application accessing the API namespace.