ATLAS.ti is a tool that supports locating, coding/tagging, and annotating features within bodies of unstructured data; it also offers visualization functions.

The software is used by researchers in a wide variety of fields, and it supports data in text, graphical, audio, video, and geospatial format.

[3] Through XML export, it also aims to provide a non-proprietary, cross-platform interface to facilitate academic collaboration.

[4][5] A prototype of ATLAS.ti was developed by Thomas Muhr at Technische Universität Berlin in the context of project ATLAS (1989–1992).

ATLAS.ti's founders have ascribed its methodological roots in part to grounded theory and content analysis.