There are several DOI registration agencies or providers worldwide. These organizations are responsible for assigning DOIs and managing the associated metadata. The DOI system operates under the umbrella of the International DOI Foundation (IDF), which sets standards and guidelines for DOI registration agencies. While the number of DOI providers may have changed since then, we can provide an overview of some well-known DOI providers as of that time:
Crossref is one of the most prominent DOI providers, primarily serving the academic and publishing communities. It assigns DOIs to scholarly articles, books, conference papers, and more. Crossref also maintains a vast database of scholarly metadata, making it a valuable resource for researchers and publishers.
DataCite specializes in assigning DOIs to research datasets. It focuses on improving the discoverability and citation of research data, which is essential for the transparency and reproducibility of scientific research.
Figshare is a multidisciplinary data repository and DOI provider. It allows researchers to share and publish a wide range of research outputs, including datasets, figures, and media. Figshare assigns DOIs to these objects, ensuring their long-term accessibility.
Zenodo is an open-access repository that assigns DOIs to a wide variety of research outputs, including datasets, software, and preprints. It is particularly popular among researchers in the open science community.
Dryad is a repository and DOI provider that specializes in hosting and curating research data associated with scientific publications. Researchers can deposit their data in Dryad and receive a DOI to link their data to their publications.
PANGAEA is a repository and DOI provider focused on earth and environmental science data. It offers long-term storage and DOI assignment for datasets related to geosciences.
mEDRA is a DOI registration agency that provides DOI services for various types of digital content, including scholarly articles, conference proceedings, and ebooks. It primarily serves European publishers and organizations.
Please note that the landscape of DOI providers is continuously evolving, with new agencies emerging and existing ones expanding their services. Additionally, the choice of a DOI provider may depend on the type of content you wish to register, your geographical location, and specific requirements or preferences. It is advisable to check the latest information and options when considering a DOI provider.
Conclusion: DOI providers play a crucial role in ensuring the persistent identification and accessibility of digital objects. The diversity of providers allows for tailored DOI services, catering to the specific requirements of different content communities.