PMC International (PMCI) is a collaborative effort between NLM, the publishers whose journal content makes up the PMC archive, and organizations in other countries that share NLM's interest in archiving life sciences literature. The long term goal of PMCI is to create a network of digital archives that can share some or all of their respective locally deposited content with others in the network. There are two primary reasons for doing this:

• The probablity of an archive surviving over the long term is greater if there are working copies of the archive in regular use at multiple sites around the world.
• A producer or funder of research literature often will be more inclined to make the primary deposit of its material to a locally or regionally affiliated archive, rather than to one operated elsewhere in the world.

To date, NLM has authorized two PMCI centers: UKPMC and PMC Canada.

UKPMC

UKPMC is sponsored by the Wellcome Trust and several other major research funders in the UK, and became operational in January 2007. At present, UKPMC receives all of its journal content directly from the U.S. PMC archive. At a later stage, it may take in some content directly from publishers or other sources.

UKPMC uses NCBI's portable PMC (pPMC) software to manage, and provide access to its content. The pPMC system displays articles in the same way as the U.S. PMC system and is similar to it in most respects.

The PMC-UKPMC collaboration is based on a formal agreement between the NLM and the UKPMC sponsors concerning the management of the archive. This agreement protects the rights of the publishers who participate in PMC, ensures the integrity of their content, and ensures that users will always have free access to the content. (See the prototype agreement.)

PMC Canada

PMC Canada became operational in October 2009, under an arrangement with NLM and NCBI similar to that for UKPMC. PMC Canada represents a partnership between the Canadian Institutes of Health Research (CIHR), the National Research Council’s Canada Institute for Scientific and Technical Information (NRC-CISTI), and the NLM. Like the UKPMC, PMC Canada receives all of its content through the US PubMed Central.

Publisher Permissions

Since July 2006, all PMC Participation Agreements have included permission to make a participating journal's PMC content available to UKPMC automatically. Publishers participating in PMC prior to July 2006 were asked for permission to deposit content in UKPMC, and most agreed to it. As a result, UKPMC mirrors the majority of PMC content.

With the introduction of PMC Canada, all current PMC participants have been asked for permission to make their PMC content available to the Canadian site. NLM will not redistribute a journal's PMC content to PMC Canada without the explicit permission of the publisher. These permissions are included automatically in PMC agreements signed in June 2009 forwards.

Future PMCI Centers

When appropriate, NLM expects to expand the PMCI network to include centers serving other countries or regions. Authorization of a new center will occur only if the following conditions are met:

• The new center must be sponsored and managed by a national or international agency with a committment to building and managing the archive for perpetuity. It may be a government agency, or a not-for-profit organization at an equivalent national or international level, formed by non-commercial entities such as universities, research institutions, funding agencies, or professional societies.
• The new center must attain an operational level that meets standards defined by the NLM, and the sponsors and managers agree to maintain that level into the future.
• The new center must sign an agreement with NLM concerning the management of the archive. This agreement protects the rights of the publishers who participate in PMC, ensures the integrity of their content, and ensures that users will always have free access to the content. (See the prototype agreement.)

When NLM decides to authorize another PMCI center, all publishers with existing PMC Agreements will be asked for permission to redistribute content to the new center. New PMC Agreements will automatically incorporate permission to distribute content to the new center.

Portable PMC (pPMC)

Portable PMC (pPMC) is a software package developed by NLM's National Center for Biotechnology Information (NCBI). It is derived from the software used to operate the U.S. PMC system at NLM. It allows PMCI centers to import data from PMC, build a local database, and display content in a presentation style very similar to PMC. The pPMC software itself does not include any rights to the PMC content.

Portable NIHMS

The NIH Manuscript Submission System (NIHMS) was developed by NCBI to facilitate the submission of final, peer-reviewed manuscripts to NIH in support of NIH's Public Access Policy. NIHMS users upload manuscripts in a wide range of electronic word-processing formats, and these manuscripts are subsequently processed and deposited in U.S. PMC.

Portable NIHMS (pNIHMS) is a portable software package version of NIHMS, also developed by NCBI. Like NIHMS, it is used to upload manuscripts for processing and deposit in U.S. PMC. The UKPMC archive presently uses Portable NIHMS for the intake and submission of manuscripts to PubMed Central. After deposit in PMC, these manuscripts are sent back to UKPMC for deposit.