> Programming languages play, within the context of cultural evolution, the same role of tongues in human language. However, instead of making communication possible among two individuals, they provide the medium to single-directed communication between humans and machines.<p>Abelson and Sussman wrote "programs must be written for people to read, and only incidentally for machines to execute". I would view, not the programming language, but the computing machine itself as equivalent to the medium in human language, whether sound waves and ink on paper. Communication of a message between two individuals must conform to the restrictions of the medium used, whether phonetic sounds air can carry, strokes recordable on paper, or syntax parsable and runnable by a certain compiler.<p>[1] <a href="http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-7.html" rel="nofollow">http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-7.html</a>