Participation Policy


Several factors define participation in the Unidata Program. The primary factors are:

  • Provision or use of scientific data sets
  • Provision or use of data analysis and management software
  • Support in the use of software and data (either receiving support or providing it to others)
  • Active participation in a virtual community of users who contribute to the development and modification of software and data resources provided by the Unidata Program Center (UPC)
  • Participation in Unidata Governance

Participation in Unidata is subject to certain terms and conditions which are set forth below. Individuals and institutions must identify themselves through a web-based registration process prior to participating. This policy describes the services available and the degree to which different organizations can participate.

Provision of Data

Unidata is not a data center. However, through collaborations within the geosciences community, Unidata gains access to data sets which are redistributed either directly or indirectly (through its user community) at no cost, using a variety of data distribution methodologies. To receive data (thus becoming an active participant in our data-sharing community), participants must be affiliated with one of the following: a degree-granting institution, or a not-for-profit institution with an education and/or research mission.

With regard to data distribution, all participants must comply with any applicable U.S. export laws and regulations. See additional information on data usage.

Sites participating in data exchange with the Unidata community may be asked to serve data to other community sites as assigned by Unidata technical staff.

Provision of Software

Software packages supported by Unidata are available by downloading from the Unidata web site. Software developed by Unidata is licensed under the Lesser GNU Public License (LGPL), or a model similar to LGPL. Other packages, developed by Unidata partners and distributed by the UPC, have specific conditions on access and redistribution. Participants are expected to review and accept the copyright or program-specific conditions for each package downloaded and adhere to them. A basic table of limitations follows:

Software Title or Group General Description of Limitations
GEMPAK/GARP GEMPAK and GARP software are freely available (full source code) to any individual or institution. Unidata will only support unmodified versions of GEMPAK subject to conditions below.
McIDAS McIDAS software (full source code) is freely available to educational institutions. Redistribution is prohibited without explicit written permission from the University of Wisconsin, Space Science and Engineering Center (SSEC), the copyright holder of this software.



These applications are copyrighted by UCAR and are intended to be freely available with very minimal restriction.
OpenDAP OpenDAP is freely available software produced and updated through a consortium of developers. It can be used,modified, altered and redistributed freely except as noted in the copyright which is held by the University of Rhode Island and the Massachusetts Institute of Technology and is subject to the terms therein.

Provision of Support

The degree to which Unidata can support its community is dependent on the resources allocated from our sponsors. Currently, there are several levels of support available from the UPC:

Support to Institutions

Unidata provides direct support via email for its software packages to institutions offering college-level courses for credit, and to non-profit institutions with education or research missions. Institutions must provide a single point of contact for direct support questions. Unidata staff will provide priority support to qualifying organizations with a geoscience focus.

Support for McIDAS software acquired through the UPC is provided under the above-conditions through the Unidata support team. SSEC (the software developers) provides support only to the McIDAS User Group (MUG) members.

Unidata provides training in the use of some of its packages. Priority for enrollment in this training is given to active participants from organizations offering courses for credit in the geosciences.

Support to Individuals

The UPC administers and maintains several topical mailing lists and support archives which act as an excellent source for problem resolution. These tools are freely available for use by any individual identified to the UPC through its registration process. Unidata does not provide direct email support to individuals who are not identified as the direct point-of-contact or technical liason for a given institution.

The UPC maintains web-based information and documentation, including Frequently Asked Questions (FAQ's) which are accessible by any individual for any purpose without constraint.

Participation in the Unidata Virtual Community

The Unidata Program Center is a small group with limited resources. The success of the UPC is heavily reliant upon the support of its user community. The more the community can help itself, the more the UPC can spend resources on software improvements, developments, and upgrades. Participants are strongly urged to participate in open, topical mailing lists that support the enhancement of data holdings and software tools distributed by the UPC.

Please see our "Terms of Use, Comments/Contributions" for more information about participation in our community.

Limitations and Exceptions

Unidata reserves the right to change its Participation Policy at any time.

Unidata will (on a limited basis) consider exceptions to policies for individuals or organizations who fall outside of the current stated policy and desire access to certain data or tools, if a collaboration can be formed which will enhance and strengthen our community as a whole.

Unidata products and products associated with or distributed by the UPC are not intended for operational use. There is no guarantee as to the quality of data or usability of any software distributed through the Program Center or any of its participating entities.

UCAR/Unidata, for itself and its sponsors, makes no representations or affirmations of fact with respect to the software or data made available to its participants. By accepting this Participation Policy, Participant understands and accepts that any product it receives from participation in the Unidata community is as is, with all faults. All express and implied warranties of any kind, including the implied warranties of merchantability for a particular purpose with respect to these products, are hereby disclaimed.

Neither UCAR nor its sponsors shall be liable for any direct, incidental, special or consequential damages of any kind arising out of the use or the inability to use, any product distributed or associated with UCAR/Unidata. Participants shall have no remedy against UCAR, Unidata, or its sponsors for use of product it receives directly or indirectly through the UPC. By accepting this Participation Policy, Participant agrees on behalf of his/her self or his/her affiliated institution that it shall indemnify and hold harmless UCAR, Unidata and its sponsors any and all liability, loss, cost or damage (including reasonable attorneys' fees) arising out of or in connection with Participation in the Unidata community.