Witness the definitive, irrefutable, immutable ranking of the most brilliant software programs ever hacked.
"Program design in the UNIX environment" a.k.a. "UNIX Style, or cat -v Considered Harmful", rob pike, brian w. kernighan.
web-based source code browser for current and historic unix versions
web-based source code browser for historic unix versions with comments from the gurus
Felix von Leitner's original paper on BSD and Linux io performance.