The Historical Thesaurus website has adapted or made use of several free and open source libraries and resources in order to enhance the presentation of the underlying data. The JavaScript library jQuery and the user interface library jQuery UI are used throughout the site for animated transitions, pop-ups, and for more behind the scenes tasks such as fetching data from the server. The jQuery plugin FancyTree was adapted to create the tree-style category browser and the jQuery plugin Tooltipster was used for tooltips. The jQuery plugin jQuery Sparklines was adapted for the mini-timelines.

The JavaScript library d3.js is used to generate the main timeline visualisations, the sparklines and the heatmap. The main timeline visualisations were adapted from the d3-timeline example, the sparklines were adapted from a tutorial found here, and the heatmap was adapted from a day/hour heatmap found here.

Icons used throughout the site are provided by Font Awesome.

The typeface used by the Thesaurus on this site and elsewhere is Concourse by Matthew Butterick. A geometric sans-serif with a wide range of weights, Concourse was loosely inspired by the 1920s typeface Metro but has more vigorous italics and some European influences.