In this paper we show how we used robust human language technology, such as our domain-independent and customisable named entity recogniser, for automatic content annotation and indexing in two digital library applications. Each of these applications posed a unique challenge: one required adapting the language processing components to the non-standard written conventions of 18th century English, while the other presented the challenge of processing material in multiple modalities. This reusable technology could also form the basis for the creation of computational tools for the study of cultural heritage languages, such as Ancient Greek and Latin.