Orthanc is free and open-source software. Its source code is freely available to the benefit of hospitals and researchers.


Mailing List

To be warned after each new release of Orthanc, please follow the Orthanc Users discussion group.


Orthanc originates from Sébastien Jodogne's research work at the University Hospital of Liège (Belgium), in the Department of Medical Physics. Orthanc is now primarily developed and maintained by Osimis S.A., spin-off company of the University Hospital of Liège. The source code is jointly copyrighted by the University Hospital of Liège and Osimis S.A. under the GPLv3 license, with the OpenSSL exception.

Please pay attention to the fact that Orthanc plugins may be released under a more restrictive license. In particular, the Web viewer, the PostgreSQL, the MySQL, the DICOMweb, and the whole-slide imaging official plugins are licensed under the AGPL license. The Stone of Orthanc C++ toolkit is also licensed under the AGPL license.

If the GPL or the AGPL is too restrictive for your usage, you can buy a license exception from the company Osimis.

More information about the licensing of the Orthanc ecosystem is available in the Orthanc Book.

Citing Orthanc

We kindly ask scientific works and clinical studies that make use of Orthanc to cite Orthanc in their associated publications. Similarly, we ask open-source and closed-source products that make use of Orthanc to warn us about this use. You can cite our work using the following BibTeX entry:

  author="Jodogne, S{\'e}bastien",
  title="The {O}rthanc Ecosystem for Medical Imaging",
  journal="Journal of Digital Imaging",

This paper is available for download in open-access courtesy of the Journal of Digital Imaging.