For people and teams developing mods and games with Valve's Source engine.
VTFEdit is a VTF texture conversion utility with a graphical interface. It can convert to and from and view all versions of the Valve Texture Format, and change the files' settings without requiring them to be recompiled.
VTFEdit is developed by Nem. Visit his website for more details.
Note that VTFEdit requires the .NET Framework 1.1 to run. Download it from Microsoft here.