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transparent image ADL-R
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transparent image CORDRA
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transparent image Digital Object Architecture
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transparent image DO Registry
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transparent image DO Repository
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transparent image DOI System
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transparent image Handle System
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transparent image Knowbot Programs
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transparent image Speech and Language
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Research and Activities


The Advanced Distributed Learning (ADL) Initiative, managed by the Office of the Secretary of Defense Under Secretary of Defense for Readiness (DUSD/R), is sponsoring an effort to specify the Content Object Repository Discovery and Registration/Resolution Architecture (CORDRA). This effort will bring together existing standards and specifications in content management and network computing with the goal of greatly enhancing the reuse and interoperability of distributed learning content compatible with the sharable Content Object Reference Model (SCORM).

One of the components selected for the project is CNRI's Handle System technology, for use generating and resolving identifiers. This system was developed as part of CNRI's DARPA-funded Digital Object Architecture research, much of which is highly relevant to ADL-R. Specifically, CNRI has designed, built, and deployed a registration system for the ADL project, known as the ADL Registry or ADL-R. This facility will enable the discovery and reuse of learning content held in repositories distributed across the DoD.

A generic version of ADL-R is under development by CNRI and the initial version, best used to clone ADL-R, is now available at Digital Object Registry. Future versions will have added configuration options and will be useable in any community of practice. Future versions will also introduce the ability to federate individual registries across communities of practice and will advance the CORDRA effort.


CORDRA is a Digital Object Registry specification being developed by CNRI. Objects are registered through the submission of structured metadata and that metadata is indexed and made searchable. Those objects that are not already identified by a persistent identifier, in the form of a handle, are assigned one by the registry which can then be used to manage that identifier for most normal operations. The first of these registries, ADL-R, was developed for the Advanced Distributed Learning (ADL) Initiative. Key to the future development of CORDRA is the ability to federate individual registries across communities of practice.

D-Lib® Magazine

CNRI produces D-Lib Magazine, an electronic publication with a primary focus on digital library research and development, including new technologies, applications, and contextual social and economic issues.

Digital Object Architecture

Digital Object Architecture includes development of core technology to be used in testbeds and implementation projects, with funding from a variety of sources. It continues the architectural work of the DARPA-funded Computer Science Technical Reports (CS-TR) project. That project developed a framework for distributed digital object key components, with testbeds at the Copyright Office and the National Digital Library Program at the Library of Congress.

See also "An Overview of the Digital Object Architecture" at hdl:4263537/5041.

DO Registry

CNRI Digital Object (DO) Registry, available for download, functions as a specialized index over a collection of digital material held in one or more repositories. Registry users provide metadata schemas, and objects are registered with their metadata. That metadata is indexed and made searchable. Objects may also be stored and managed by the DO Registry, and that object is assigned, or assumed to already have, a persistent identifier in the form of a handle.

DO Repository

CNRI Digital Object (DO) Repository enables the management of digital objects on the Internet. It is now available as a download, and comes with an open source license and includes an open, flexible, secure and scalable protocol and software suite that provides a common interface for interacting directly with all types of digital objects through an interface that is based on the use of identifiers and can be applied to existing repository or storage systems.

DO Store

The DO Store provides downloadable software that comprises reference implementations of components of the Digital Object Architecture (DO Architecture). Included here are links to the DO Repository for managing digital objects and the DO Registry for accessing metadata about digital objects. Click here to enter the DO Store.

DOI® System

CNRI is working with the International DOI Foundation (IDF) to support the DOI System, a standard method for identifying content objects in the digital environment, using the CNRI Handle System as the underlying technology.

Handle System®

The Handle System is a general purpose distributed information system that provides efficient, extensible, and secure HDL identifier and resolution services for use on networks such as the Internet. It includes an open set of protocols, a namespace, and a reference implementation of the protocols.

Knowbot Programs

Knowbot Programs are mobile agents intended for use in widely distributed systems like the Internet. CNRI is developing an infrastructure for Knowbot Programs. A free prototype implementation in Python is now available for evaluation. An implementation in Java™ is being developed that has digitally signed knowbots and uses the Handle System for identifying service stations and entities that sign mobile agents.

MEMS and Nanotechnology Exchange®

The MEMS and Nanotechnology Exchange is a leading provider of high-quality foundry and consulting services for the MEMS community. In its role as a trusted intermediary, the MEMS and Nanotechnology Exchange acts as a broker between customers and a network of fabrication facilities. That network of state-of-the-art facilities collectively offers the most comprehensive and diverse set of implementation solutions for MEMS, micro- and nano-technologies, to be found anywhere in the world.

Speech and Language Processing Center

The Speech and Language Processing Center fosters research and development for technology in both spoken and written human language. Spoken language projects aim to enable humans to interact with computers using natural conversation, while text-based projects address issues of evaluation, component integration and handling multiple data sources.


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