The digital humanities are an interdisciplinary field of research concerned with improving and facilitating the work of traditional humanities through the study, development and application of information technology. One aspect within this field is the analysis of digital texts or digitized text corpora using appropriate text analysis methods. In this context, visualization can be an invaluable tool as it enables an interactive, explorative analysis process that allows researchers to discover new knowledge that may be lost otherwise. Application scenarios include visualizing the topics occurring in blogs, news articles, and emails, visual sentiment analysis, and visualizing events and trending topics in streaming text data. This thesis should perform a survey of visualization techniques that supports humanities scholars in studying digital texts and data derived from the former.