S3M is the file format used by the popular ScreamTracker 3 PC music tracker, developed by Psi of the famed demoscene group Future Crew.
The S3M format is an advanced module format, and is the successor to the STM format used by the original ScreamTracker. Both formats are based on the original MOD format used on the Commodore Amiga computer.
S3M improves on its predecessors by supporting:
- More channels (32 instead of 4 in MOD/STM)
- More instruments (99 instead of 31 in MOD/STM)
- More effects, such as stereo panning
The additional capabilities of S3M have resulted in much more developed and higher-quality music over the MOD format. Up until the SDL port, however, MegaZeux was unable to directly play S3M music, requiring that it first be converted into the GDM format. With the SDL port's move to ModPlug and MikMod libraries, however, it is possible to play S3M's natively in MZX.