| Microsoft Visual Studio Launch Wizards Format | |
| Microsoft | |
| Ads |
Windows
| .a | Unix Static Object Code Library Format |
| .a2w | Alice Program World Format |
| .actx | DS Game Maker Action Description Format |
| .ada | ADA Language Source Code Format |
| .addin | Microsoft Visual Studio Addin Format |
| .ads | Ada Package Specification |
| .agi | Asterisk Gateway Interface Format |
| .alb | Alpha Five Data Dictionary |