- Not to be confused with the Sirius XM satellite radio service, with which it has nothing to do.
XM (extended module) is an audio format introduced by (and primarily produced by) FastTracker 2, a now defunct tracker for MS-DOS. The format is also used by other trackers, such as DigiTracker and MilkyTracker.
The tracker which produced the file can be identified by means of the 20-byte string at offset 38 (0x26):
|FastTracker 2||"FastTracker II"|
|OpenMPT||"OpenMPT " and then the version number|
|AmigaMML||By default, "AmigaMML " and the version number; can be changed|
|MilkyTracker||"MilkyTracker " (with 8 padding spaces)|
- Original file format documentation by Mr.H of Triton (1994), included with the FT2 distribution as "Xm.txt"
- The above, with a number of corrections and additions (link seems to be dead?)
- Errors in the XM format documentation
- Mr.H documentation with corrections by Guru and Alfred of Sahara Surfers (1995) (pastebin mirror)
- Further corrected version of the above (pastebin mirror)
- A more complete file format documentation, by ccr@tnsp (2001) (pastebin mirror)
- "The Unofficial XM File Format Specification", Vladimir Kameñar, 2007