The file extension AS identifies source code files in the scripting language ActionScript. It is a Macromedia (now Adobe) language developed for the control and generation of interactive Flash applications. Actionscript can also be used with the Adobe Flex and Air products, providing the ability to create rich Internet applications, desktop applications (via AIR), and apps for the iPhone, iPad, and Google Android.
The files are pure text files that can be opened and edited in any text editor. For the development environment Eclipse there is the ActionScript Development Tool (ASDT).
Most often resolving problems with opening AS files is very simple. Just install an appropriate program that supports such files. All of the listed programs support AS files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of AS files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate AS files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Adobe Dreamweaver applications is not on the list, select "Browse" option in order to manually locate the directory where Adobe Dreamweaver has been installed.
Sometimes problems with opening AS files may not lie with the application itself, but can arise due to other causes, such as: