| Diamond Directive Format | |
| Microsoft | |
| Ads |
Files with the .DDF extension contain compression properties of CAB files in the form of plain text.
CAB files contain information needed to install Windows programs and do not contain DDF files themselves. DDF files contain only a set of compression settings that the resulting CAB file was subjected to. CAB files can be read and edited in any text editor, but they should not be modified without a clear necessity.
Windows
| .a2theme | Aston 2 Theme Format |
| .acb | Adobe Color Book Format |
| .acbl | Adobe Color Book Format |
| .aco | Adobe Photoshop Color Palette And Swatches Format |
| .acrobatsecuritysettings | Adobe Acrobat Security Settings Format |
| .acrodata | Adobe Acrobat Data Format |
| .acv | Adobe Photoshop Colour Curves Format |
| .acw | Microsoft Accessibility Wizard Format |