Half Life 2
VTF Explorer is a tool for viewing and extracting Source Engine format texture files (.vtf's - Valve Texture Files).
VTF Viewer (as name tells) is a tool for viewing Source Engine format texture files. Program allows you to view whole folder full of VTF's and other image files as a collection of thumbnails.
This utility will convert all the .vtfs in a folder to .tga and delete the vtfs afterwards if wanted.