.DM3 File Extension

Raster image created by DigitalMicrograph, a application used for viewing and analyzing captured microscope images; stores the image and includes metadata such as the microscope's CCD camera properties, the exposure length, and a timestamp; uses a proprietary format.

Game demo created by the 1.11-1.16 point releases of Quake 3 Arena; contains a recording of gameplay that can be played back in the software by choosing Demos, selecting the DM3 file, and then clicking Play.

NOTE: The Quake 3 1.32 patch uses .DM_68 files for demos.

A DM3 file is a disk information file created by Diskette Manager 3, an MS-DOS disk cataloging program. It specifies a disk's name, description, file list, and related metadata. Diskette Manager 3 places a DM3 file on each disk you catalog using the program.

Diskette Manager 3 is a program that allows users to catalog all their diskettes and floppy disks, as well as those disks' contents, in a single database. The program also allows users to print adhesive labels that detail each cataloged disk's contents. Users can apply these labels to their disks to make searching for a specific disk easier.

When a user catalogs a disk using Diskette Manager 3, the program places a DM3 file on that disk. Each disk's DM3 file includes all that disk's cataloged information, including the disk's name, contents, comments, date cataloged, type, and bytes used.

Because DM3 files are plain text files, you can open and edit them in any text editor, such as Microsoft Notepad (Windows), Apple TextEdit (Mac), or GitHub Atom (multiplatform).