I'm confused about hook_theme. I should have been paying more attention to that discussion. It seems to duplicate a lot of the functionality of the existing render api. I was wondering if someone could help me understand the differentiation and use cases for the similar features? A quick overview of functional duplication... The hook_theme 'arguments' property seems like it would be roughly equivalent to the way element property default values are set using _element_info. The hook_theme 'function' property seems very similar to how '#theme' functions currently. The hook_theme 'preprocess' property seems very similar to the render api's '#pre_render' The hook_theme 'override preprocess' seems to provide the same functionality as hook_view_alter... .darrel.