The list author says: "These are the "timeless" books that every programmer should have on their bookshelf. You won't find books with titles like "Teach yourself Turbo Pascal in 21 days"; Instead, you'll find books that still hold their value decades later."
"You need to know a language that is close to the machine. That language is C: a small, expressive, and powerful language. It's the language used by most systems level software, it's the language used to write Unix, Linux, and Windows. Every programmer should know some C."
"Scheme is a functional language, on the opposite end of the spectrum from C. Functional programming will teach you an entirely new way of thinking about problems. Whereas C more closely models the way a computer works, Scheme more closely models the way computation works."