MDX file format is used by DEAMON tools software application. This file is used as an archive file which is used to store metadata of the file and in some cases this file format can also be used to store the data of CD/DVD.

This file format is used to store the disc image like MDS or MDF file formats but in case of MDX a single file contains all the stored data. The data stored in MDX file if it is used as a metadata storing file includes sessions, tracks, layer breaks and other information. At the start of the file a number is added which is called Media Descriptor.