.ACS2 File Extension
What is an ACS2 file?
Skin file used by AIMP, a free music player; stores a skin for the user interface; includes panel and container layout, border color, font, and text color information.
To add a skin to AIMP, place the ACS2 file in the C:\Program Files\AIMP[version]\Skins directory. Then go to Skins in the AIMP application, select your skin, and click Apply.
NOTE: The ACS2 file can be created and edited by the AIMP2 Skin Editor.