Philologic is a free, open source full-text search, retrieval and analysis tool developed by the ARTFL Project and the Digital Library Development Centre, at the University of Chicago. This tool supports a wide variety of XML and SGML encoded documents, in addition to plain text, Dublin Core and HTML, and includes a MySQL back end. It is designed ot be light, fast and robust, boasts extensive use and testing, and can be used directly 'out of the box' with numerous configuration options built in.

Juxta is a free, open source tool for comparing and collating texts, originally intended for comparing multiple versions of the same text. It offers several views and visualization options, including histograms and side by side comparison. Juxta is available as both a desktop application and as a web service that can be integrated into the user's own website.

Virtual Lightbox is a Java-base tool for comparing images online developed for the academic humanities, the library and museum community, and any users who use images as an important data type. It is available as both an application, which functions as a virual whiteboard and includes peer-to-peer, and an applet, which provides a flexible environment for image comparison. Virtual Lightbox was first developed in 2000, with version 2.0 of applet released in 2004.

Structured Parallel Coordinates is a free JavaScript data visualization tool offered by EURAC. It is intended for data that contains some kind of structure, such as temporal ordering, strings or ranked orderings. EURAC has provided several examples, such as ngram comparisons, (sub)corpus comparison and KWIC with live corpus queries.

The Juxta family of software (Juxta, Juxta WS, and Juxta Commons) allows you to compare and collate versions of the same textual work. Juxta Commons is an online space powered by the open-source Juxta Web Service that lets you collate sets of two or more texts and share online visualizations of the differences between them. Side-by-side or "heat map" visualizations can be viewed on the Juxta Commons site, while embedding codes are available for sharing a compact version of the heat map visualization on your own blog or website. Collation results can also be output as an XML file with TEI parallel segmentation markup, or as a Word document or HTML file with a base text and traditional textual apparatus. Development of Juxta Commons was sponsored by NINES.

Superfastmatch is designed to find exact duplicates of text strings between documents.