OCFL: An application-independent file layout for repositories

The Oxford Common File Layout (OCFL, https://ocfl.io/) specification describes an open and application-independent approach to the storage of digital objects in a structured, transparent, and predictable manner. It is designed to promote sustainable long-term access and management of content within digital repositories. Repository content — that is, the digital files and metadata that a repository might manage — is typically much more durable than the repository software application. By providing a specification for file layout, the OCFL is an attempt at reducing, or even eliminating, the need for time consuming and risky data migrations associated with software transitions. The resulting structure supports deployment and replication using filesystems and object store technologies, and provides a basis for shared tooling. The OCFL specification builds on experience with the BagIt specification and the Moab design to support strong fixity checks and to provide a simple structure to efficiently capture versions of object contents so that all previous states of an object may be recovered and examined. This presentation will focus on the motivations and vision for the OCFL, explain key choices in the specification, and describe the status of implementation efforts.