| xm | FastTracker 2 Music Module |
| xma | Xbox 360 Native Audio |
| xmf | Extensible Music Format File |
| xmf0 | Extensible Music Format File |
| xmf1 | Extensible Music Format File |
| xmi | Extended MIDI Song |
| xms | XMS Tracker Module |
| xmz | FastTracker 2 Extended Module |
| xmz | ZynAddSubFX Master File |
| xopus | Exient XGS OPUS Audio Data |
| xp | FastTracker 2 Pattern |
| xpm | Akai MPC Software Program |
| xrni | Renoise Instruments Data |
| xrns | Renoise Song |
| xsb | XACT Sound Bank |
| xsm | eXtra Simple Music Data |
| xsml | iRomplerMap Audio Data |
| xspf | XML Shareable Playlist File |
| xt | Fast Tracker 2 Music Track |
| xvag | Sony PlayStation 3 Audio File |
| xwb | XACT Wave Bank |
| xwm | Microsoft xWMA Compressed Audio |
| xwma | Microsoft xWMA Compressed Audio |
| xwv | Valve Xbox360 Audio Data |
| yadpcm | Yamaha 4-bit ADPCM Format RAW Data |
| ym | Atari ST Audio Data |
| ynx | Seqmax Seqprest Compressed Audio |
| ytif | Yellow Tools Independence Image |
| ytil | Yellow Tools Independence Instrument Library |
| z00 | Casio WK-3000 Rythm Data |
