| .73c |
TI-73 Constant File |
| .73l |
TI-73 Data List File |
| .accdb |
Access 2007 Database File |
| .adp |
Access Project |
| .as |
ActionScript File |
| .adt |
ACT! Document Template |
| .aw |
Answer Wizard File |
| .arc |
Norton Backup Archive |
| .avp |
Avid Project File |
| .a5w |
Alpha Five Webpage File |
| .adcp |
Adobe Device Central Project File |
| .adf |
ACT! Data File |
| .ans |
ANSI Text File |
| .art |
ArtCAM Model |
| .ade |
Access Project Extension |
| .asm |
Assembly Language Source Code File |
| .ask |
askSam Database |
| .aft |
Ancestry.com Family Tree Database |
| .adx |
Approach Index File |
| .awg |
Activeworlds Object Group File |
| .ab1 |
DNA Electropherogram File |
| .abi |
DNA Chromatogram File |
| .acr |
Audio Comparer Results File |
| .abcd |
AudioVisual Book Data File |