.asc files can easily be opened as a simple text file by various programs. In Windows, you can use text editors like Editor and Wordpad. However, if you want to open an .asc file using an Office program, you’ll have to activate conversions. If you don’t, the .asc file will still open but may not be displayed correctly.
.asc files that are meant to be used with ActionScript can be created with the Adobe Media Encoder or the Flash Media Live Encoder. Free programs like Mozilla Thunderbird and SeaMonkey, the code editors Notepad, Notepad++ and Notepad2, Gpg4win, and the GNU Privacy Guard can also open .asc files. Mac users can use Apple’s TextEdit, in addition to the various Adobe programs.