| .afc |
Mass Effect 2 Audio File |
| .at3 |
ATRAC3 Audio File |
| .avastlic |
Avast! License File |
| .arx |
AutoCAD Runtime Extension File |
| .ase |
Adobe Swatch Exchange File |
| .acroplugin |
Adobe Acrobat Plug-in |
| .arc |
Norton Backup Archive |
| .azw1 |
Amazon Topaz eBook |
| .a5w |
Alpha Five Webpage File |
| .als |
Ableton Live Set File |
| .amxd |
Ableton Max Patch File |
| .a2c |
Alice Object File |
| .azw3 |
Amazon KF8 eBook File |
| .azw4 |
Amazon Print Replica eBook |
| .aqm |
AlpineQuest Map File |
| .adf |
ACT! Data File |
| .aac |
Advanced Audio Coding File |
| .aiff |
Audio Interchange File Format |
| .ace |
WinAce Compressed File |
| .ans |
ANSI Text File |
| .art |
ArtCAM Model |
| .au |
Audacity Audio File |
| .ade |
Access Project Extension |
| .asm |
Assembly Language Source Code File |