Juxta is an open-source tool for comparing and collating multiple witnesses to a single textual work. Originally designed to aid scholars and editors examine the history of a text from manuscript to print versions, Juxta offers a number of possibilities for humanities computing and textual scholarship.

As a standalone desktop application, Juxta allows users to complete many of the necessary operations of textual criticism on digital texts (TXT and XML). With this software, you can add or remove witnesses to a comparison set, switch the base text at will. Once you’ve collated a comparison, Juxta also offers several kinds of analytic visualizations. By default, it displays a heat map of all textual variants and allows the user to locate — at the level of any textual unit — all witness variations from the base text. Users can switch to a side by side collation view, which gives a split frame comparison of a base text with a witness text. A histogram of Juxta collations is particularly useful for long documents; this visualization displays the density of all variation from the base text and serves as a useful finding aid for specific variants.

The desktop version of Juxta also allows users to annotate Juxta-revealed comparisons and save the results, and can output a lemmatized schedule (in HTML format) of the textual variants in any set of comparisons. It can run on any modern Macintosh, Windows, or Unix computer with Java 1.5 installed.

Juxta has also been developed as a web service with a limited set of the features available in the desktop application. This web service can be integrated into a host site and controlled via a well-documented API. This web-service powers Juxta Commons, the destination site for using Juxta on the web. No download is necessary: simply upload or link to your sources and start collating! Screencasts and a user guide are available, and the R&D team would appreciate your feedback during this beta release.

The source code for Juxta is distributed under the Apache License and available on GitHub. There are separate public repositories for the desktop and web service versions of Juxta. There is a Google Groups forum for developers.