Since libraries are increasingly involved in journal publishing, HathiTrust [ 11 ], a shared preservationquality digital repository, is a natural place to archive and provide access to journal literature to ensure its long-term preservation and discoverability. HathiTrust already archives and provides access to reformatted library holdings, but the University of Michigan Library, a founding member of HathiTrust, sees an opportunity to use HathiTrust for publishing borndigital journals as well. To develop an infrastructure in support of low-cost university-based publishing that addresses the needs and values of both content creators and librarians, the U-M Library is funding the creation of mPach [ 12 ], an open-source, end-to-end publishing system in which the act of publishing and the act of archiving are unified. In other words, archiving in HathiTrust happens as a byproduct of publication rather than being carried out after the fact. mPach leverages existing components of HathiTrust and available opensource software where appropriate.

Archiving is not as simple as saving a copy of a file produced by a journal editor, as OJS and institutional repositories generally do. Instead, the content needs to be stored in a format that allows digital preservation. PDF/A, a non-proprietary variant of the PDF family standardized as ISO 19005, is often suggested for such needs, but even a PDF/A file is poorly suited for use with screen readers for the visually impaired and for any non-paginated display, and is suboptimal even for searching and data mining.

Rather than preserving the paginated appearance of a document, the text of the article needs to be stored in a format that reflects its structure and semantics, with associated media in formats that can be preserved and rendered. mPach has developed a specification for journal articles that uses the Journal Article Tag Suite (JATS), an application of NISO Z39.96-2012 [ 13 ], for the text and stores this with high-quality versions of media objects and with a METS record containing structural and preservation metadata.

There are three major parts of mPach (see also figure 1), each of which includes components in various stages of development at the time of writing: • the peer review and editorial system: what authors and reviewers interact with • Prepper: what prepares the article for ingest into HathiTrust for archiving and publication • modified HathiTrust components: various modifications to existing components of the HathiTrust environment to support born-digital journal articles

As a modular system, mPach could be used with any peer review and editorial system that is capable of interacting with Prepper; however, the developers have chosen to provide OJS as the default option. Despite having no support for digital preservation, OJS is already widely used for library-based journal publishing, and mPach’s integration with this software will allow for a smooth transition of journals already published using OJS into the HathiTrust repository. Integration with mPach requires that manuscripts that reach the “layout” stage in OJS be sent to Prepper, which prepares the HathiTrust Submission Information Package (SIP).

Prepper provides a user interface for the editor of a journal: a dashboard for administering the journal and putting manuscripts through a production process—akin to composition and typesetting—that prepares all content according to the preservation standard developed for mPach content in HathiTrust. Prepper invokes Norm, a Python application developed to convert manuscripts from Office Open XML (“DOCX”) format [ 14 ] into XML that conforms to JATS. DOCX is the default option because, like OJS, it is widely used in the editorial process of journals published by libraries. The Prepper interface also guides the staff member through a review of validation errors detected by Norm’s conversion, uploading highresolution figures, supplying “alt text” for figures, previewing the article as rendered using the default stylesheet (based on the Preview XSLT stylesheets [ 15 ]), uploading supplementary material [ 16 ], and submitting for ingest into HathiTrust.

mPach requires a number of significant modifications to HathiTrust components and workflows originally designed to support reformatted print materials. The reading interface in HathiTrust, which previously supported only rendering of digitized page images, renders JATS XML in HTML and allows a user to download a dynamically generated PDF and EPUB, display metadata specific to articles (figure 2), and link to a special “collection” for the journal in HathiTrust’s Collections application [ 17 ] that allows for browsing volumes and issues of the journal (figure 3).

Discovery of known items in HathiTrust using metadata like title and author is currently provided for by a catalog of MARC records, with one per item in the repository. For mPach, each article has its own analytic catalog record, tied to a monographic record for the journal as a whole. Finally, the HathiTrust Data API [ 18 ] allows for the content of each article to be retrieved for use outside of the native HathiTrust interface.

Note that by policy HathiTrust only closes access to content for legal reasons, not because a rightsholder wants to restrict access. Therefore, mPach only supports the publishing of open-access journals.

In the typical workflow for publishing a journal using mPach, a journal editor uses OJS to manage submissions, peer review, and the editing process. Once an article reaches the “layout” stage (where a combination of composition and typesetting allows the article to be formatted in a consistent way), the journal editor formats it according to a predefined list of styles in Microsoft Word and submits the article in DOCX to mPach’s Prepper, which guides the editor through conversion to JATS XML, preparation of the SIP, and submission for ingest. Prepper keeps track of articles so that a revised version can be submitted for ingest. Currently the ingest process overwrites any previous version of an item with the same identifier, but eventually HathiTrust will archive past versions and allow users to navigate among them.

The U-M Library plans to host the Prepper system, including the submission module, to facilitate authorized deposit of content, and will make this system available for use by organizations wishing to publish journal literature in HathiTrust. The developers envision extending the Norm component to handle OpenDocument (“ODT”) [ 19 ] and LaTeX as input formats, each of which is more commonly used in certain communities. Furthermore, if the Book Interchange Tag Suite [ 20 ] is adopted as a standard, the mPach architecture might be extended to support monograph publishing. While mPach is currently being developed to meet the needs of the U-M Library, the contribution of the sourcecode to the planned HathiTrust Development Environment should foster contributions from developers not at U-M and therefore lead to the creation of a truly shared infrastructure for publishing open-access scholarly journals.