DDS File

The DDS (DirectDraw Surface) container file format, from Microsoft, is a standard for storing data compressed with the lossy S3 Texture Compression (S3TC) algorithm. This makes the format useful for storing graphical textures and cubic environment maps as a data file, both compressed and uncompressed. Textures in SimCity 2013 are typically stored in DDS format, and are packaged together with RW4 geometry files to create in-game 3D objects.

DDS Plugins
Photoshop

DDS Support & Texture Tools for Photoshop

GIMP

DDS Plugin on GIMP.org