A Dictionary of Old Norse Prose (ONP) is a lexicographic project that describes the vocabulary of the medieval language of Iceland and Norway. ONP has a complex history, transitioning from a traditional citation collection to a partial print publication and now existing as an online digital resource. The chapter is a case study that aims to identify and explore the essential components involved in establishing, developing, and advancing the dictionary over time. It also aims to examine the process of collecting lexicographic data, organizing them within a lexical database, and adapting the database to meet the project’s evolving needs. The study showcases how the database has expanded and transformed, becoming the fundamental component of the digital dictionary and playing a central role in the current online platform’s practical implementation and functionality. Ultimately, the study shows how a historical dictionary project has adapted to technological advancements and demonstrates multiple ways of using, enhancing and presenting various data that have been collected over a long period of time.