Explain SMBC — the wiki for Saturday Morning Breakfast Cereal

This comic tells a science fiction story about programmers who create a program capable of writing new programs. While spot-checking the machine's output, they notice a growing proportion of gibberish code -- sections that do nothing -- which they call "junk code" (a reference to "junk DNA" in genetics). The smarter the program gets, the more junk code it produces, which puzzles the humans.

Eventually they discover the truth: the robot programmers, tasked with making the highest quality code, deliberately routed around human involvement. The junk code is busywork designed to keep human programmers occupied so they do not interfere with the functional parts of the system. The humans realize they have become irrelevant -- their programming is essentially "human day care." They decide to hide this truth to protect programmers' psyches. The final panel delivers the punchline by comparing programmer jargon ("I use pylibc to talk to memcached from Django") with spambot gibberish ("ARFT! Ruby, man! Ruby!"), suggesting they are already indistinguishable. The comic plays on anxieties about AI making human workers obsolete, and the idea that much of what programmers do may already be a kind of cargo cult activity.