XDM, xdm, or similar can refer to:
Computing
edit- X display manager, a part of the X Window System architecture
- XDM (display manager), the default display manager included with the X Window System
- XDM (file format), the Extensible Device Metadata open format for including depth maps and other metadata in standard image files
- XQuery and XPath Data Model
- Cross-document messaging, that works around the limits set by the same origin policy in a web browser
Firearms
edit- Springfield Armory XD-M, a pistol series sold in the United States by Springfield Armory, Inc.
Gaming
edit- XDM: X-Treme Dungeon Mastery, a role-playing game supplement by Tracy Hickman, Curtis Hickman and Howard Tayler.