I've become interested in the different subtitle file formats, and here is a list of the ones I've come into contact with:
| Name | Extension(s) | Format | Comments |
| Advanced SubStation Alpha | .ass | Text | Widely used by fans who do subtitles |
| Synchronized Accessible Media Interchange | .smi | Text | Microsoft format now happily rare |
| PGS subtitle format | .sup | Binary | Subtitle format used on Blu-Ray movie |
| SubRip Text | .srt | Text | Basic but very useful subtitle file format |
| VobSub format | .idx/.sub | Text / Binary | Subtitle format used on DVD movies |