.AS3PROJ File

The as3proj file extension is associated with the FlashDevelop, an open source (MIT license) source code editor and used for one of its default project file type.

These as3proj files are ActionSript 3 projects created using the program.

An as3proj file extension is related to the FlashDevelop and used for its project files.

How to open:

You can open and continue to work on these projects in FlashDevelop.

How to convert:

Probably can be converted to other formats.