The Metadata Encoding and Transmission Standard (METS): From Presentation to Preservation: Presentation - iPRES 2005 - Göttingen
As a result of different solutions to describe documents, which had been invented with digitization efforts in US libraries in the mid 90ies, the "Metadata Encoding and Transmission Standard" derived. The idea was to use a common format for different media types (text, image, audio and video streams), which is very flexible to support different document models and allows the usage of several metadata formats. The "Metadata Encoding and Transmission Standard" (METS) is a container format to describe digital documents. Derived from early metadata description formats as used in "Making of America", it provides a flexible container format not only for digitized printed material but also for other digital media as audio and video streams. A METS-file keeps all information about the document's associated objects together - including structural data, metadata and contentfiles. Though METS allows the description of complex objects, METS files can be very simple. The only required object is a structural map which may provide optional links to metadata- and fileobjects.
The first METS files were used for presentation purposes of digitized material using XSLTs to create a TOC from the structural map and to implement simple page turner-software to browse image by image through the book (METS file contains metadata about the images and provides a link to the TIFF or JPEG file). As documents are getting more complex and the requirements to store the content are changing, more and more institutions are using document management systems (DMS) to implement repositories. A DMS provides additional and improved functionalities for retrieval, management of content files, template engines, administration toolkits etc. This functionality becomes available for METS files as well, as more and more DMS support METS as their Submission Information Package (SIP).
Preserving content for a long time is still a technical challenge, which requires specialized systems. These systems are not only responsible to preserve the bitstreams, but also for storing all necessary administrative data, which might be useful for future migration etc. These systems are usually compliant with the OAIS model using SIPs and DIPs for ingesting and exporting data from the archive. METS as a standarized container format is a good choice to import/export data to/from OAIS compliant systems. Preservations metadata as defined by PREMIS fits into the administrative metadata section of a METS document. Currently the preservation requirements are driving the ongoing development of METS. For version 1.5 of the METS schema an extension is discussed to allow pointing into file-archives as tar and zip to e.g. attach metadata (and other associated objects) to embedded files. 
["Enders, Markus"]
["göttingen"]