retrieval systems. For this purpose, JPSearch puts forward an abstract image search and retrieval framework. Interfaces and protocols for data exchange between the components of this architecture are standardised, with minimal restrictions on how these components perform their respective tasks. The use and reuse of metadata and associated metadata schemas is thus facilitated. A common query language enables search over distributed repositories. Finally, an interchange format allows users to easily import and export their data and metadata among different applications and devices. In the JPSearch framework, interoperability can be defined in different ways: between self-contained vertical image search systems providing federated search, between layers of an image search and retrieval system so that different modules can be supplied by distinct vendors, or at the metadata level such that different systems may add, update, or query metadata.