Ideas for a chronicle front-end for Emacs:

Splatches of text representing function calls, data accesses,
breakpoint hits, stack frames, data values.  Each has local key
bindings to find callers (functions), hits (for breakpoints),
modifications (for values), and so on.  Text marked as invisible,
so buffers can be saved and revisited.  Easy to produce charts like

callee
<- caller
   <- caller

Indentation significant; tree-sensitive navigation bindings.