| Abbreviation | Definition |
|---|---|
| AIN | Compressed file archive (Ain) |
| AIO | APL file transfer format file |
| AIP | Adobe Illustrator Plug-In |
| AIR | Automatic Image Registration |
| AIS | ACDSee Image Sequence file |
| AIS | Array of Intensity Samples Graphics file |
| AIX | HP NewWave Cardfile Application Datafile |
| AL | ALAW format Sound file |
| ALB | Graphics album (JASC Image Commander) |
| ALB | JASC Image Commander Graphics ALBum |
| ALF | Eclipse Application Life-Cycle Framework |
| ALG | ARCSOLO Activity Log |
| ALIAS | Alias image file 24-bit RGB RLE Bitmap graphics |
| ALL | Always Format file for working pages |
| ALL | Arts & Letters Library (Symbol and font files) |
| ALL | FRQView Filelist of all files |
| ALL | WordPerfect for Windows General printer information |
| ALM | All Luggage Missing |
| ALO | Almanac support file |
| ALPHA | Raw ALPHA bytes Bitmap graphics |