TextureBuilder 1.0 for Mac can be downloaded from our website for free. This free software for Mac OS X is a product of Heiko Irrgang. The application lies within Design & Photo Tools, more precisely Viewers & Editors.
From the developer:
TextureBuilder is a freeware program to simplify the task of building several texture formats from 6 skybox images, like our Skybox Textures.
You can load 6 different images, representing the front, back, left, right, up and down-side of a cube and combine them to either.
You may want to check out more software for Mac, such as Smith Chart for Mac or Movie2Shot, which might be related to TextureBuilder.