A while back, we have introduced a concept of Core themes. In standard WordPress theme, Core theme is a child theme for a main theme called xScape Core. So far, we have 3 Core themes, and all the other old themes will be converted to Core version soon. Future themes will be Core only.
xScape Theme Framework 1.7 is most powerful theme framework for WordPress, and this 10 minutes introduction barely scratches the surface of what xScape can do, with emphasis on minimizing the need for coding and modification of theme files: power and ease of use.