| .adf |
ACT! Data File |
| .aaxplugin |
Avid Audio eXtension Plugin File |
| .ao |
ActionOutline Outline File |
| .amf |
Additive Manufacturing 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 |
| .aifc |
Compressed Audio Interchange File |
| .ade |
Access Project Extension |
| .asm |
Assembly Language Source Code File |
| .asx |
Microsoft ASF Redirector File |
| .adr |
Opera Bookmarks File |
| .abk |
Automatic Backup File |
| .axx |
AxCrypt Encrypted File |
| .aip |
Advanced Installer Project |
| .a2w |
Alice World |
| .atn |
Photoshop Actions File |
| .asl |
Photoshop Style |
| .ask |
askSam Database |
| .aft |
Ancestry.com Family Tree Database |
| .ax |
DirectShow Filter |