.AS3PROJ File Extension

Project file created by FlashDevelop, a free source code development software often used for Flash and Web programming; saved using XML formatting and contains project information such as included source code files, build settings, and output .SWF options.

ActionScript 3 projects can be created by selecting Project → New Project in the software. The AS3PROJ file and the supporting project directories and files are saved to the directory that you specify in the dialog window that appears. The program manages all information in the AS3PROJ file, so developers do not have to edit it manually.