FEDORA

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FEDORA

• Selecting and Implementing an Open Source Digital
  Repository
• Corey Keith
• ckeith_at_loc.gov

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Introduction

• History
• FEDORA Overview
• Object Oriented Principals
• LCs Requirements
• LCs Architecture
• Review

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Pop Quiz

• XML
• OAIS
• METS
• FEDORA
• DSPACE

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FEDORA History

• Continuing Research Project
• Cornell 1997
• Prototype Application
• University Virginia
• Fedora 1.0
• Open Source Release 2002
• Fedora 1.2
• Tomorrow!

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Options, options, options

• Very few tools directly compete with each other
• Many tools can be used to accomplish similar
  behavior
• Many tools fulfill parts of the functionality
  needed for a repository
• Roll your own solution

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Why Fedora?

• Repository Architects Developers Excited ?
• Object oriented approach to digital objects
• Open Source Project
• Funded development (and support)
• Java Based
• Multiple HW Platforms

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Flexible

• Integrates well with existing systems
• CGI Scripts
• Web Services
• Leaves most decisions to implementers

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Extensible

• Again, no product can do it all
• Imaging, Audio, Transformations, Courseware
• Easy to add new functionality to objects
• Embraces web services
• Open APIs
• Access
• Management

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Digital Object

• What is the definition of a digital object?

• Documents, such as articles, preprints, working
  papers, technical reports, conference papers
• Books
• Theses
• Data sets
• Computer programs
• Visualizations, simulations, and other models

• Multimedia publications
• Administrative records
• Published books
• Bibliographic datasets
• Images
• Audio files
• Video files
• Reformatted digital library collections
• Learning objects
• Web pages

list taken from the dspace.org website
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Repository Architecture

• Objects
• Behavior Definitions
• Behavior Mechanisms
• API
• Management
• Access

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Object Oriented

• A software design method that models the
  characteristics of abstract or real objects using
  classes and objects.
• Proven Techniques for Software Development
• Requirements gathering Use Cases
• Developers speak to librarians and other
  stakeholders
• Facilitates reuse of functionality
• Design Patterns
• Not hacking Perl Scripts to make an institutional
  repository

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Object Oriented

• Data
• Metadata
• MODS Descriptive
• METS Structural
• MIX, etc Technical
• Bit streams
• Actual Files JPG, TIF, WAV, MP3, TEI, EAD
• Methods (Behaviors)
• Do stuff with the data

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Object Oriented Concepts

• Classes
• Objects of the same type belong to a class
• Interfaces
• A contract defining behaviors a class of objects
  will implement
• Encapsulation
• Behaviors operate on the data in an object
• Reflection
• Discover what interfaces and behaviors an object
  implements

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Image Objects

• Two File Image Object
• Data
• Hi Resolution Version tif
• Low Resolution Version jpg
• MrSID File Image Object
• Data
• MrSID File

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Basic Image Interface

• getHighResolutionTIF
• getLowResolutionJPG

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Basic Image Interface Implementations

• Two File Image Object
• getHighResolutionTIF
• returns high resolution TIF
• getLowResolutionJPG
• returns low resolution JPG
• MrSID Image Object
• getHighResolutionTIF
• processes the MrSID file to return a high
  resolution TIF file of the image
• getLowResolutionJPG
• processes the MrSID file to return a low
  resolution JPG of the image

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Sheet Music Object

• Data
• MODS Metadata
• Images of the pages (Image Objects)
• TEI encoded text of the lyrics (TEI Objects)
• Behaviors
• getPageImage(Pagenumber)
• Invoke the getLowResolutionJPG to return the
  image!
• getMODS
• getLyrics

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FEDORAs Interface Implementation
Behavior Definition Object
Data Object
Behavior Mechanism Object
graphics taken from presentations available at
www.fedora.info
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What is FEDORA?

• Plumbing
• Manage associations between objects and their
  interfaces
• Invoke behaviors from an interface which an
  object subscribes
• Manages or references files

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What FEDORA currently does not do?

• Digital Library in a Box
• Requires integration and custom development
• Prescribe the right way to do things
• Implementers are free to choose
• Best practices still being fleshed out

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LCs Requirements

• Complex Digital Objects
• Structurally
• METS structMap
• Rich descriptive metadata
• Exploiting MODS features
• relatedItem

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Choosing Repository Software

• Fedora provides a foundation to build on
• LC member of initial deployment team
• No other software is like FEDORA
• Except general purpose programming languages

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How LC is implementing FEDORA

• Types of Digital Objects
• Sheet Music
• Scores
• Sound Recordings
• Compact Discs
• Manuscripts
• Photographs
• Websites
• Collections
• Less emphasis
• Intellectual output of universitys research
  faculty

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METS Profiles

• Correlates well with classes of objects
• Articulates
• Structure of an object
• Metadata requirements
• METS documents conforming to profiles are
  ingested into repository
• Atomization
• Behavior association

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Architecture
user

• Fedora (Repository)
• Cocoon (Application Layer)

web browser
cocoon
Fedora Service APIs
Fedora Repository System
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SIP vs AIP

• Complex digital objects are atomized into small
  reusable objects upon ingest to FEDORA
• Sheet Music METS Profile (SIP)
• Sheet music object (AIP)
• Structural metadata encoded in METS
• Descriptive encoded in MODS
• Image objects for each page (AIP)
• TIF and JPG Files
• Technical encoded in MIX
• TEI object for the lyrics (AIP)
• TEI File

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Why this Architecture?

• Clean Separation of Concerns
• Logic Makes it go!
• Content From FEDORA
• Style Web Designers
• Object not bound to display
• Repository is for preservation of metadata and
  files not markup (HTML)
• Markup accomplished in cocoon layer
• Leverage use of METS structural metadata
• Performance Cocoon Caching

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User Interface Development

• Web Designers
• Relate to objects and behaviors
• Can develop in HTML for display
• XSLT
• Uses XML from repository to drive display

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Other Pieces of the Repository Puzzle

• Other open source tools
• Cocoon
• XML Publishing Framework
• Lucene
• Text Indexing and Search API
• Someone has to write software!
• Java to build Lucene indexes
• XSP searching
• More XSLT than you want to see

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Digital Object Production

• How are we building these digital objects?
• MySQL
• Cocoon
• XSLT
• Homegrown Java
• Technical metadata extraction

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Cocoon

• XML Publishing Framework (Toolbox)
• Generate
• From files (or URLS)
• From databases
• From code (XSP, JSP, PHP)
• Transform
• XSLT
• Serialize
• XML, HTML, PDF, SVG, MIDI?
• Caching

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XSLT

• Philosophy
• Get data into XML as early in the workflow as
  possible
• Flexibility
• Easy to change logic in XSLT
• No need to recompile
• Performance Issues

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Resources Needed for FEDORA (Cheap)

• Hardware Requirements
• Minimal for experimentation
• Installs on Windows PC
• Packaged to get up and running quickly
• Demo set of objects
• Scales with hardware in a production environment

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Resources Needed for FEDORA (Expensive)

• 1 or More Developers
• 1 Kick the tires
• or More Real production
• Application Architects
• Requirement Analysts
• Subject Matter Experts
• Articulate requirements
• Object Structure
• Descriptive Metadata

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Summary

• Five Questions
• Who
• What
• When
• Why
• Where

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Who

• Institutions with resources to do software
  development
• Unique requirements for digital library software
• Preexisting tools do not fit the need
• Need for integration of existing systems into one
  management infrastructure

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What

• Digital Library Plumbing
• Very general purpose
• Use it to build almost any digital library
  application

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When

• December 10th Version 1.2

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Why

• Robust Set of tools to build YOUR repository
• User support high from FEDORA development team
• Smart people working on hard problems

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Where

• www.fedora.info

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Questions