40 Theological librarianship • Vol. 12, No. 1 april 2019

Twenty Years of Theological Markup Languages: A Retro- and Prospective

by Race J. MoChridhe

Abstract: ThML—the first open, XML-based markup language designed specifically for digital libraries handling theological collections—was conceived in 1998, sparking a period of development in discipline-specific markup languages for theology that lasted until the early 2000s, when the dominance of the TEI standard led the field to stagnate. Despite the disappearance of the active developer communities behind most of the projects and technical improvements in TEI, however, ThML and other languages developed during that period remain in use. After present-ing a brief history of theology-specific markup, this article seeks to understand what its persistence tells us about the discipline-specific needs of biblical and theological studies that are still not being met by TEI, and offers insights as to the lessons that may be drawn from these projects for the future of theological markup.

In 1998, Harry Plantinga, a computer science professor at Calvin College, began work on the Theological Markup Language (ThML)—the first open, XML-based markup language designed specifically for digital libraries handling theological collections.1 Over the past two decades, ThML has provided critical technical infrastructure to a wide range of projects, both academic and popular, that have disseminated theological literature to millions of users. In 1999, a consortium of leading organizations in biblical studies and Bible publishing started development on projects that became the Open Scripture Information Standard (OSIS)—another XML-based language intended for specialized theological use. This markup, too, made its way into a wide array of projects, and it was particularly favored by Bible translators and publishers. Throughout the early 2000s, these two flagship initiatives were joined by a host of smaller endeavors with much more limited adoption: OpenSong (XMM), Unified Scripture Format XML (USFX), Zefania XML, and others. By 2006, however, interest in discipline-specific markups for theology began to wane as wider adoption of the Text Encoding Initiative (TEI) encoding schema—a technical standard meant to promote compatible styles and expressions of XML across disciplines—increased in appeal to a variety of digital humanists. By the end of the 2000s, the period of active markup development specific to theology projects had largely come to an end.

Nevertheless, the tools developed over the preceding years, particularly ThML and OSIS, remain in use even until today, despite their now limited interoperability and lack of active development and support. This essay briefly surveys the history of these projects and their distinctive features in an effort to understand why they have not been replaced. Analysis shows that, despite TEI’s refinement over the past twenty years, many of the critiques made by developers of discipline-specific markups for theology remain unaddressed, such that TEI remains a suboptimal tool for certain kinds of discipline-specific work. The paper concludes by identifying elements of ThML and OSIS that might still be profitably incorporated into TEI, either as custom extensions for current projects or, potentially, as canonical additions to future TEI versions.

A Brief History of Theology-Specific (XML) Markup

Just as the Bible was the first book to be set by movable type, so it was also one of the earliest texts to receive specific attention for computer encoding. By the late 1990s, decades of work had produced a plethora of

1 Harry Plantiga, “ThML: Theological Markup Language for the Christian Classics Ethereal Library,” Christian Clas-sics Ethereal Library, February 23, 2001, http://www.ccel.org/ThML/ThML1.02.pdf.