| .3mf |
3D Manufacturing File |
| .3dxml |
Dassault Systemes 3D XML File |
| .3dmdef |
3DMark Definition File |
| .atom |
Atom Syndication Format |
| .alx |
BlackBerry Application Loader XML File |
| .application |
ClickOnce Deployment Manifest File |
| .aepx |
After Effects XML Project |
| .as3proj |
FlashDevelop ActionScript 3 Project File |
| .amf |
Additive Manufacturing File |
| .art |
ArtCAM Model |
| .afploc |
Apple Filing Protocol Location |
| .addin |
Visual Studio Add-in Definition File |
| .apd |
ACDSee Photo Document |
| .aetx |
After Effects XML Project Template |
| .as2proj |
FlashDevelop ActionScript 2 Project File |
| .anx |
HotDocs Answer File |
| .alp |
Ableton Live Pack File |
| .aws |
AutoCAD Work Space File |
| .ath |
Alienware AlienFX Theme File |
| .aml |
ACPI Machine Language File |
| .atomsvc |
Atom Service Document |
| .arxml |
AUTOSAR XML File |
| .axp |
CDBurnerXP Audio Compilation File |
| .ariax |
Chipsounds XML Sound File |