There's also a command-line driven program to do texture shading, which is available now for Windows as well as Mac. (The source code is also included, so you could even compile it for Linux or another operating system if you want.) It's not as user friendly, and it has no additional features except to compute the texture shading, but it's the exact same core algorithm as in Terrain Texture Shader. You can download the software and user guide at app.box.com/textureshading/. My slide presentation from the 2010 NACIS conference is also there, for anyone interested in what the algorithm does.