1. A computer system, comprising: (a) a computer display; (b) a memory configured to store at least a portion of a body of knowledge representing a collection of information about a predetermined topic, the body of knowledge stratified into a plurality of levels of abstraction including at least first and second levels of abstraction that are respectively associated with first and second development threads, the body of knowledge including a plurality of chronologically-arranged information elements, at least a portion of which associated with at least one of the first and second levels of abstraction; and (c) a processor, coupled to the computer display and memory, the processor configured to access the body of knowledge in the memory and to concurrently display on the computer display first and second representations of a common portion of the body of knowledge, the first and second representations respectively displaying first and second information elements respectively associated with the first and second levels of abstraction such that the first and second development threads are concurrently presented to the user.