ac3d 7.5.02 for Mac can be downloaded from our website for free. This software for Mac OS X was originally developed by Inivis Limited. The program is included in Design & Photo Tools.
From the developer:
AC3D is used to create 3D models for games; virtual-reality/simulation software; scientific, medical, and general-data visualizations; high-resolution 3D renderings and rapid prototyping of 3D designs.
You may want to check out more Mac applications, such as Verto Studio 3D or Prefab3D, which might be related to ac3d.