XCode, as any other IDE I know, shows you the source files as a hierarchy of files and folders - a tree. Recently I realized that a better way to browse the source for me is a dependency diagram - a directed graph (this graph should be also be acyclic if I did everything right). So, I have a couple of questions for my fellow hackers:
1. Are there tools that help build and visualize dependency graphs? In particular, for Objective C but any other language is also interesting.
2. Are there IDEs (or IDE plugins) that use dependency graph as the primary way of browsing code, in lieu of the directory structure?
http://www.gnu.org/software/cflow/
It's primitive compared to the stuff you find in with more reflective languages, at least Common Lisp and Smalltalk, or for that matter binary analysis utilities like IDAPro.
But, theoretically, you could do that only with C-like languages and binary executables: i.e. languages that have a "program entry point".