For Developers

NSDL provides a broad set of tools and services that help the education community to organize, manage, and disseminate digital educational content to advance STEM teaching and learning.

Developers from education projects, digital libraries, educational and research institutions use these tools and services when partnering with NSDL or as stand-alone applications. These tools and services may be either hosted by NSDL or installed locally. Read the NSDL Technical Overview for more information about these tools and services and the NSDL technical platform. NSDL develops and supports most of these tools while others may be provided through NSDL partners.

At a glance. . .

For more information on utilizing tools and services, please contact us.


Create, Manage and Catalog Collections

  • The NSDL Collection System (NCS) - a  flexible XML-driven tool providing a metadata editor, collection workflow processes, and a role-based permission system to support distributed and collaborative collections management. The NCS can support any metadata framework defined by an XML schema and transparently writes metadata and collection-level information to a repository. The NCS is available for hosted use at, or may be downloaded for local use.

  • Collection Workflow Integration System (CWIS) is a turnkey, web-based software package designed to allow groups with collections of information to share that information with others via the World Wide Web and integrate that information into the NSDL. CWIS conforms to international and academic standards for metadata, supports user ratings and annotations, and is easily customizable, integrating readily with other open source packages such as Drupal and phpBB. CWIS was developed and is supported by Internet Scout.

  • The Digital Discovery System (DDS) software is an XML repository search server tool that provides a search API built on top of Lucene. A DDS repository can be populated through a repository service API or by pointing it to XML files on disc. It is optimized to support the rapid construction of audience-specific portals and applications and can be flexibly configured to search over any XML structure.

  • Most NSDL services utilize the NSDL_DC metadata format, with a URL being required. This is a variation of the qualified Dublin Core format. Metadata formats that incorporate Dublin Core elements can be translated or crosswalked when sharing resources with NSDL. Other metadata formats can be submitted to NSDL. 

    • NSDL needs to work closely with metadata providers when the metadata format is unknown to NSDL, in order to configure NSDL metadata ingest processes to accept the new format. 

    • The NSDL_DC Metadata Guidelines provide a review of what metadata is, how it works in NSDL and how it can be shared with NSDL. They also provide metadata information, definitions and controlled vocabularies specific to creating the NSDL_DC format. 

    • For information on crosswalks, XML schemas that NSDL develops, and other questions go to the FAQ for NSDL_DC Metadata

    • See NSDL Technical Documentation for more information

Search NSDL Resources and Collections

  • The Search API allows developers to embed and reuse NSDL resources and collections directly in websites and learning applications.


Harvest Metadata and Collections


Align Resources with Educational Standards

  • The Strand Map Service (SMS) APIs enable the construction of interactive knowledge map interfaces based on the learning goals articulated in the American Association for the Advancement of Science (AAAS) Benchmarks for Science Literacy. An example of a Strand Map Interface can be found at the NSDL Science Literacy Maps

  • Content Assignment Tool (CAT) assists collection providers, catalogers and teachers in assigning educational content standards by providing suggestions of relevant standards. The system stores these human-vetted assignments and utilizes machine learning techniques in order to improve its own auto-suggestions. CAT was developed at the Center for Natural Language Processing (CNLP) at Syracuse University.

  • The Achievement Standards Network (ASN) provides tools and databases that enable access to and interaction with the authoritative collection of learning and content standards from states, US national, and other national content groups


Share Resources and Collections

  • NSDL uses the Open Archives Initiative (OAI) Protocol for Metadata Harvesting (PMH) interoperability standard to share and harvest metadata about resources and collections. jOAI is a free tool that may be used to harvest records via OAI-PMH. Additional information on OAI best practices, sharing metadata , and FAQ may be helpful. 

  • NSDL is sharing NSDL metadata and paradata (usage information) with downstream STEM education communities of users via their own platforms and/or learning management systems (LMS), as well as with groups partnering with the national Learning Registry project. Please contact usif you would like to know more or are interested in collaborating to add NSDL content to your learning management system.