DDS
DDS (DirectDraw Surface) is an texture format developed by Microsoft for DirectX 7 which stores textures in formats that can read directly by the GPU. Although designed for DirectX, it also sees frequent use with non-DirectX APIs due to its popularity.
Counter-Strike: Global Offensive uses DXT1-compressed DDS files for radar images.
Counter-Strike Nexon: Studio uses DDS files for textures instead of WAD files.
DDS files can be remuxed to or from VTF or VTEX_C files without image reencoding, however mipmaps will need to be rearranged; DDS stores mipmaps from largest to smallest, whereas VTF and VTEX_C store mipmaps from smallest to largest.
