Reader's interface

Readers access collections using a Web browser

Multi-platform server

Digital library server runs on any version of Windows, Macintosh (OS X), Linux, or other Unix versions

Librarian's interface

Librarians design and build collections, and add documents and metadata, using an interactive interface

Documents

Ingests all standard document types, e.g. HTML, Word, RTF, PDF, PostScript, Powerpoint, Excel, e-mail

Multimedia

Ingests multimedia objects, e.g. images (GIF, PNG, JPEG, TIFF . . .), audio (MP3, Ogg Vorbis, WAV . . .), video (MPEG, Quicktime, RealMedia . . .)

Metadata

Ingests all standard metadata types, e.g. XML, MARC, OAI, METS, CSV, CDS/ISIS, ProCite, BibTex

Metadata sets

Defaults to Dublin Core but can use any metadata set; incorporates metadata set editor to create ones

Extensibility

"Plug-ins" can be written to accommodate new document and metadata types

Searching

Full text is searchable by default; librarians can add indexes of (any combination of) metadata elements 

Browsing

Librarians can add linearly or hierarchically browsable lists of any metadata elements

Access structures

All access structures are created automatically; no links are inserted by hand

Indexers

Incorporates a choice of full-text indexing software: MG, MGPP and Lucene

Incremental operation

Can operate incrementally when documents are added to or deleted from collections

Scheduled rebuilding

Includes end-user facilities for scheduling regular rebuilding of collections

Interoperability

Serves and harvests OAI-PMH; exports and ingests to/from METS and DSpace; harvests over Z39.50 and SRU; ingests MediaWikis

Multilingual content

Unicode is used internally and converted on the fly to a coding standard supported by the user’s Web browser.

Multilingual interface

Reader's interface is available in 50 languages; librarian interface and documentation are available in several languages

User authentication

Built-in access control mechanism for collections and  individual documents to authorized users

Logging

(Optionally) records all user actions

Dynamic operation

Collections can be updated and new ones brought online at any time, without disturbing users

Publishing collections

Collections can be published on removable media such as CD-ROM/DVD/USB flash drive

Distributed librarians

Authenticated users can modify collections on a central server using a remote version of the Librarian interface

Large scale

Existing collections have 10 M documents, 20 GB of raw text, 2 B words, 50 M unique terms 50 GB metadata

Space-efficient

Uses compression to reduce the size of indexes and text

License

Free open-source software issued under the GNU General Public License

Support

Mailing lists in several languages; support centers in India and Africa; several commercial support organizations exist