Program Composition and Transformation in Unix

A few years ago, I got the feeling that language design could benefit from looking towards Unix and the lessons of the Unix culture.
A definite source of inspiration for this was Eric S. Raymond's The Art of Unix Programming, which among other things analyze what the greatest strengths and most significant design decisions (or rather, design style elements) of Unix are.

One of the qualities I'd most like to carry over from Unix to programming languages has to do with modularity - the ease with which one can combine small components into great things; components which in themselves are simple and easily understood.