<p>CATMA (Computer Aided Textual Markup &amp; Analysis) is a free, open source markup and analysis tool from the University of Hamburg's Department of Languages, Literature and Media. It incorporates three interactive modules: (1) The tagger enables flexible and individual textual markup and markup editing. (2) The analyzer incorporates a query language and predefined functions. It also includes a query builder that allows users to construct queries from combinations of pre-defined questions while allowing for manual modification for more specific questions. (3) The visualizer provides basic visualization options for texts and corpora. CATMA also interfaces with the Voyant toolset. As of version 4.1, CATMA is a web application with collaborative work functions, and improvements to its user interface, queries and corpus analysis capacity. Version 4.2 offers, among others, new visualization options.</p>