| .acz |
AppCraft Project |
| .a7p |
Authorware 7 Project |
| .a7r |
Authorware 7 Runtime File |
| .afdesign |
Affinity Design Document |
| .aria2 |
aria2 Control File |
| .arn |
Autoruns Data File |
| .aseprite |
Aseprite Sprite File |
| .afphoto |
Affinity Photo Document |
| .afm |
Adobe Font Metrics File |
| .api |
Adobe Photoshop Inks File |
| .ahx |
WinAHX Tracker Module |
| .ac5 |
ArtCut 5 Document |
| .ac6 |
ArtCut 6 Document |
| .all |
Java RMI Policy File |
| .ais |
ACDSee Image Sequence File |
| .a5l |
Authorware 5 Library |
| .a65 |
Authorware 6.5 File |
| .aswcs |
Avast! Compressed Skin File |
| .aos |
ARCHOS PCtablet Firmware File |
| .apm |
Aldus Placeable Metafile Image |
| .ab2 |
Print Shop Address Book File |
| .as4 |
askSam Backup File |
| .arh |
ProTool Compressed Project File |
| .afs |
STAAD.foundation Project File |