| aop | JBoss AOP File |
| ap | WebSuite Active Page |
| ap3 | VS10XX VSOS Application |
| api | WebObjects API File |
| aplt | AppleScript Applet |
| app | Visual FoxPro Application |
| appc | Oracle WebLogic APPC Data |
| applescript | AppleScript Script |
| applescript | AppleScript Script Bundle |
| applet | Eclipse IDE Java Applet Policy Data |
| appodeal | Appodeal SDK Data |
| appup | Erlang Application Upgrade File |
| appx | Microsoft Windows 8 App Package |
| appxbundle | Microsoft Windows 8.1 App Bundle Package |
| appxbundlemanifest | Microsoft Windows 8.1 App Bundle Manifest File |
| appxsym | Windows 8 App Package Symbols |
| appxupload | Windows 8 App Upload Package |
| aps | Uniface Startup Shell Data |
| aps | VS Binary Resource Script Data |
| apw | Adobe Authorware Packaged Data |
| apx | WebSuite Compiled Active Page |
| aqf | Aquifer CMS Page |
| arbfp1 | ARB Fragment Shader Program |
| arbvp1 | ARB Vertex Shader Program |
| arc | BASIS ASCII Resource Data |
| arcv | Crestron SIMPL Archive Manifest Data |
| armi | Carbide ARMI Project |
| armx | ASP.NET Source Code |
| arnoldc | ArnoldC Source Code |
| aro | SteelArrow Web Application |
| arq | Remedy ARS Macro |
| arsc | Android Package Resource |
| as | Adobe Flash ActionScript |
| as1 | ActionScript 1.0 Source Code |
| as3 | ActionScript 3.0 Source Code |
