| advixeexp | Intel Advisor Results Data |
| advs | Adobe Device Central Device Set |
| ael | Asterisk Extension Language Source Code |
| aet | FileMaker Pro Runtime Database |
| aex | Alpha Five Compiled Library Script |
| agc | AfterGRASP Compiled Script |
| agi | Asterisk Gateway Interface |
| agls | Adobe GoLive Snippet |
| ago | Autolog Script |
| agq | Altair GraphQL Client Data |
| agwl | Abstract Grid Workflow Language Data |
| ahr | Omnis Studio Ad hoc Report |
| ahtml | Amulet Module Main OS File |
| aidl | Android Interface Definition Language Data |
| aio | APL Transfer Format File |
| aj | AspectJ Source Code |
| al11 | SAP ABAP AL11 Transaction Code |
| alan | Alan v3 Source Code |
| alb | Alpha Five Library |
| alm | Alpha Five Data |
| alx | Alpha Five Script Data |
| am | GNU Automake Input File |
| amos | AMOS Source Code |
| ane | Adobe AIR Native Extension |
| ani | Valve Source Model Animation Data |
| animevents | Amazon Lumberyard Animation Events Database |
| animgraph | Amazon Lumberyard Animation Graph Data |
| animset | FaceFX Animation Set Data |
| animset_ingame | FaceFX In-Game Animation Set Data |
| ansym | Adobe Edge Animate Symbol Data |
| anv | Anastasia Style |
| aop | JBoss AOP File |
| ap | WebSuite Active Page |
| ap3 | VS10XX VSOS Application |
| api | WebObjects API File |
