LaTeX package file created in the DOCTex format; includes both source and documentation in the same file, meaning that both the user manual (the documentation) and the LaTeX component to be installed (e.g., a new style or class) are present in the file; used for distributing LaTeX packages.

DTX files almost always come with a corresponding .INS installer file that extracts the DTX content into separate files (e.g., .STY or .TEX files). Run the INS file in your LaTeX application to extract the files.