UML


The Unified Modeling Language, a great excuse for grown-ups to draw lots of things with markers on whiteboards with the excuse that they're trying to design software that works.

Think of it as the modern equivalent of trying to ensure the hunt will be successful by drawing a bison on your cave wall. The big difference is that you don't have to spray charcoal and clay with your mouth.

Resources:

Tools for UML work in Mac OS X: