Software Archaeology

"This isn't programming, this is archaeology"! the programmer complained, wading through the ancient rubble of some particularly crafty pieces of code. It's a pretty good analogy, actually. In real archaeology, you're investigating some situation, trying to understand what you're looking at and how it all fits together. To do this, you must be careful to preserve the artifacts you find and respect and understand the cultural forces that produced them. But we don't have to wait a thousand years to try to comprehend unfathomable artifacts. Code becomes legacy code just about as soon as it's written, and suddenly we have exactly the same issues as the archaeologists. What are we looking at? How does it fit in with the rest of the world? And what were they thinking? It seems we're always in the position of reading someone else's code: either as part of a code review, or trying to customize a piece of open source software, or fixing a bug in code that we've inherited.