MO3 is a music file format developed by Ian Luck. MO3 files are tracker modules

MOD (file format)

MOD is a computer file format used primarily to represent music, and was the first module file format. MOD files use the “.MOD” file extension, except on the Amiga where the original trackers instead use a “mod.” prefix scheme, e.g. “mod.echoing”...

 that contain samples encoded in the MP3

MP3

MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...

 or Ogg Vorbis

Vorbis

Vorbis is a free software / open source project headed by the Xiph.Org Foundation . The project produces an audio format specification and software implementation for lossy audio compression...

 file formats, rather than straight PCM

Pulse-code modulation

Pulse-code modulation is a method used to digitally represent sampled analog signals. It is the standard form for digital audio in computers and various Blu-ray, Compact Disc and DVD formats, as well as other uses such as digital telephone systems...

 samples . This results in a greatly reduced file size for the module, while maintaining almost identical audio quality. Lossless audio encoding is also supported, for samples that do not compress well with lossy encoding.

The format's name is a portemanteau of MOD

MOD (file format)

MOD is a computer file format used primarily to represent music, and was the first module file format. MOD files use the “.MOD” file extension, except on the Amiga where the original trackers instead use a “mod.” prefix scheme, e.g. “mod.echoing”...

 and MP3

MP3

MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...

 . Despite the name, four other tracker formats are supported besides MOD: Scream Tracker 3

Scream Tracker

Scream Tracker is a tracker . It was created by Psi of Finland's Future Crew It was coded in C and assembly language. The first popular version of Scream Tracker, version 2.2, was published in 1990...

 (S3M), Fast Tracker 2

Fast Tracker

FastTracker 2 is a tracker created by Fredrik "Mr. H" Huss and Magnus "Vogue" Högdahl, two members of the demogroup Triton which set about releasing their own tracker after breaking into the scene in 1992 and winning several demo competitions. The source code of FastTracker 2 is written in Pascal...

 (XM), Impulse Tracker

Impulse Tracker

Impulse Tracker is a multi-track digital sound tracker . It was one of the last tracker programs for the DOS platform. It was authored by Jeffrey "Pulse" Lim, and example music was provided by Jeffrey Lim and Chris Jarvis...

 (IT), and MultiTracker (MTM).

External links

• MO3 unofficial specifications, with source code
• XMPlay - an audio player that supports MO3 files
• XMP - XMP supports MO3 files
• FAP - Fox Audio Player supports MO3 files
• OpenMPT - OpenMPT is a Tracker that can open and edit (but not save) MO3 files