About OpenGrey


  • OpenGrey is a multidisciplinary European database, covering science, technology, biomedical science, economics, social science and humanities.
  • The records are in English. They include bibliographical data, the SIGLE classification codes with their wording, and possibly an English abstract (starting in 1997).
  • Each record has either an English title and/or English keywords.
  • Document types include technical or research reports, doctoral dissertations, conference papers, official publications, and other types of grey literature.
  • The user is informed of the availability of the document and the conditions of access for paper documents from each supply centre.

Partners: SIGLE / EAGLE

OpenGrey is operated by INIST-CNRS. OpenGrey combines the resources of major European information and document supply centres who joined in an association known as EAGLE : European Association for Grey Literature Exploitation.

Each centre was responsible for collecting grey literature produced in its own country. It also helps you to obtain a copy of the paper document, if no other information is available in the reference.

OpenGrey also includes the conference preprints of our partner GreyNet International annual conferences on grey literature GL.

Technical information

User interface: OpenGrey uses the Exalead search engine for the database, with in-house developments based on php and MySQL software for the user interface. Exalead offers powerful search queries as well as facetted search. The User interface has been designed using the php framework Pxxo.

Export facilities: OpenGrey is OAI-PMH compliant and its contents can be harvested. It further offers the possibility to export references in xml format or with Zotero

Metadata. : OpenGrey records are based on an enhanced version of the qualified Dublin Core format. Each record in the present OpenGrey database is identified by a unique persistent identifier, the “handle”.


  • SIGLE - System for Information on Grey Literature, was created in 1980 in order to collect and to make available grey literature produced in the countries of the European Community by the intermediary of an online database.
  • Created with the support of the European Community, the base was produced from 1985 onwards by EAGLE - European Association for Grey Literature Exploitation. Each country is represented by one or more documentation centres or libraries of national importance.
  • In 2005, the members of EAGLE decided to dissolve the association and to stop the input of new documents. The database SIGLE was taken from all hosts proposing the database online.
  • In the context of the Open Access movement INIST-CNRS (Institut de l’Information Scientifique et Technique) then launched the OpenSIGLE project. It decided to transfer the SIGLE database to a DSpace platform and to make its contents freely available as OpenSIGLE.
  • In 2009-2010, GreyNet International joins OpenSIGLE, adding the preprints of the GL conference series to the repository. By providing full text access to the conference papers it offers open access to international research on grey (gray) literature.
  • In 2011 OpenSIGLE changes its platform and its name. OpenGrey provides new features and new content.
  • Thus all bibliographical references are searchable again, free of charge, with OpenGrey.