This free Mac app was originally produced by Klink! Software. The program lies within Games, more precisely Tools.
From the developer:
dim3 (was dimension3) is a 3D action "game without content." This engine is aimed directly at mod makers and anybody interesting in creating their own 3D game. These people have done wonderful things with other engines, but they are extending an engine that was basically designed for a single game. Dim3 is the opposite ... an engine designed for all games!
You may want to check out more Mac applications, such as World of Warcraft Interface AddOn Kit or Virtual Combat Cards, which might be similar to dim3.