| Document Type Definition Format | |
| N/A | |
| Ads |
DTD is a developer file that specifies XML document structure. DTD format is used along with HTML or XHTML files and are commonly referenced in file headers, seldom in URLs.
DTD files only in web-related projects. DTD file should follow best programming practices and use UTF-8 encoding. The main advantage of separate files is the option to refer to them in muliple XML files of a project.
Windows
Mac OS
Linux
| .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 |
