Implementing "Light-weight Reference Models" in MyLibrary


This text describes how a particular portal application -- MyLibrary -- is implementing a few "light-weight reference models" as described by OCKHAM. MyLibrary is primarily intended to provide a customizable interface to library collections of Internet resources, but it also provides the means to export its data via various formats and protocols including dynamically created HTML, static HTML, OAI, RDF, ODBC, and SQL. Using these various formats and protocols the MyLibrary application/system enables other applications to use the MyLibrary data for other library-related purposes such as the creation of path-finders, interlibrary-loan requests, statistics gathering, etc. This presentation illustrates how some of this is being implemented and solicits input from the audience on how the process can be improved as well as what steps should be taken next. A PDF version of this text is also available at: .


Since 1998 MyLibrary has represented an extensible implementation of a user-centered, customizable interface to a library's collection of information resources. [1] The system integrates principles of librarianship with globally networked computing resources creating a dynamic, customer-driven front-end to any library's set of materials. It supports a framework for libraries to provide enhanced access to local and remote sets of data, information, and knowledge. At the same time, it does not overwhelm its users with too much information because the users control exactly how much information is displayed to them at any given time. The system is active and not passive; direct human interaction, computer mediated guidance, and communication technologies, as well as current awareness services, all play indispensable roles in its implementation. MyLibrary is open source software distributed under the GNU Public License. To date it is in production in a couple of dozen libraries across the world, and it has been used as a model for other portal-like applications.

In May of this year the Digital Library Federation (DLF) sponsored a meeting at Emory University to discuss a concept coined OCKHAM (Open Community Knowledge Hypermedia Administration and Metadata). [2] The purpose of OCKHAM is to articulate and design a set of "light-weight reference models" for the purposes of enabling system components to talk to one another in a library environment. Using the vocabulary of the Open Archival Information System (OAIS), a "reference model" is:

A framework for understanding significant relationships among the entities of some environment, and for the development of consistent standards for specifications supporting that environment. A reference model is based on a small number of unifying concepts and may be used as a basis for education and explaining standards to a non-specialist. [3]

The qualifier "light-weight" is our own addition. It is used to inspire the mathematical elegance -- simplicity -- of the reference models and protocols we are trying to create. Think Occam's Razor. We consider the Hypertext Transfer Protocol and the Open Archives Initiative (OAI) on top of that protocol to be good examples of "light-weight".

Initial Experience

The MyLibrary application/system is made up of a relational database and a (large) Perl module. The distribution comes with a set of scripts implementing the Web-based customizable user interface as well as the Web-based interface for administrators. Additional scripts have been written against the module, one of which, a script allowing the administrator to create RDF files from the underlying database [4]. These files, in turn, could be used to create HTML pages via XSL. Alternatively, they could be transformed into other file types such as MARC, XMLMARC, or channels for other portals.

For demonstration purposes a set of PHP scripts was written illustrating how content from the underlying database could also be shared via OAI. In their present state the scripts are functional, OAI version 1.1 compliant, but also rather "brain dead" since they only provide access to a particular information type in the database. [5] The possibilities for this sort of functionality include current awareness services, federated searching services, backup/mirroring routines, etc.

These implementations applied against the MyLibrary application/system are considered "light-weight" because they are simple, targeted, non-proprietary, and require very little overhead. Next steps might include the application/system's ability to read RDF, harvest data via OAI, or generate standard ILL requests by implementing NCIP (NISO Circulation Interchange Protocol).


  1. The MyLibrary home page is located at .
  2. A travel log documenting my experiences at the first OCKHAM meeting are at .
  3. Don Sawyer and Lou Reich. "Reference Model for an Open Archival Information System (OAIS)," CCSDS 650.0-B-1 (January 2002), pg. 12 .
  4. For more information about see
  5. For more information about MyLibrary's present OAI interface see .

Creator: Eric Lease Morgan <>
Source: This text was prsented at ECDL, September 2002, Rome, Italy.
Date created: 2002-09-10
Date updated: 2004-12-04
Subject(s): presentations; OCKHAM (Open Community Knowledge Hypermedia Administration and Metadata); ECDL (European Conference on Digital Libraries); MyLibrary;