Extensible Metadata Platform

"The Extensible Metadata Platform (XMP) is an ISO standard, originally created by Adobe Systems Inc., for the creation, processing and interchange of standardized and custom metadata for digital documents and data sets.

XMP standardizes a data model, a serialization format and core properties for the definition and processing of extensible metadata. It also provides guidelines for embedding XMP information into popular image, video and document file formats, such as JPEG and PDF, without breaking their readability by applications that do not support XMP. Therefore, the non-XMP metadata have to be reconciled with the XMP properties. Although metadata can alternatively be stored in a sidecar file, embedding metadata avoids problems that occur when metadata is stored separately."

‘Embedding metadata in files allows easy sharing and transfer of files across products, vendors, platforms, without metadata getting lost; embedding avoids a multitude of problems coming from proprietary vendor-specific metadata databases.’

‘XMP can be used in several file formats such as PDF, JPEG, JPEG 2000, JPEG XR, GIF, PNG, WebP, HTML, TIFF, Adobe Illustrator, PSD, MP3, MP4, Audio Video Interleave, WAV, RF64, Audio Interchange File Format, PostScript, Encapsulated PostScript, and proposed for DjVu. In a typical edited JPEG file, XMP information is typically included alongside Exif and IPTC Information Interchange Model data.’

For file formats that have no support for embedded XMP data, this data can be stored in external .xmp sidecar files.

It also looks like XMP supports custom XMP schemas – could this be a bridge to Resource Description Framework (RDF) and JSON-LD?

See formats and metadata.