ASWS files contain data and values for relevant and changeable display properties and are used by the Avast! anti-virus software in order to change the display properties of the Avast! program windows. Among the various display properties that may be changed by a new skin are the colors, animation, transparency, scale, and textures. These changes will also apply to any child windows, including pop-up dialog boxes.

These files are created by skin development software such as ActiveSkin.