This is one of the coolest tools to come along in a long time. It does just what the name would suggest... it allows you to view maps. It works a lot like Forge's visual mode... except it has a few extra features. Up and down motion is supported (shades of Pfhorte's viewer), and maps can be viewed fully-textured down to wireframe, with almost anything in between. It requires OpenGL, a 3D-rendering interface which is becoming quite common. OpenGL on a 3dfx card requires full-screen mode, which the Viewer doesn't support, but if you have an ATI Rage Pro or Rage 128 (or, according to Apple, ...