Systems access non-compatible content repositories that are not natively accessible to a content management system. A metadata registry maintains metadata about content stored in both compatible and non-compatible repositories. For content in a non-compatible repository, the metadata indicates a repository interface capable of accessing the non-compatible repository. The content manager communicates with the repository interfaces to access the content in non-compatible repositories. The content manager may receive a request for content in a non-compatible repository, refer to the metadata registry to select a repository interface to employ, transmit a request for the requested content to the selected repository interface, and receive the requested content from the repository interface. A repository interface registry maintains information about available repository interfaces. Entries may be added to either the metadata registry and the repository interface registry, thus allowing the systems to be extended to be able to access additional non-compatible repositories.