I yesterday finished the best book I have read about zen so far. Paul Reps and Nyogen Senzaki are the compilers of this excellent book called "Zen Flesh, Zen Bones". It contains 101 Zen Stories (also found in internet), The Gateless Gate (zen koans), The 10 Bulls (or "the ox-herding pictures") and Centering. So it is actually four books in one. I think Mud Zen koans are ready for "The 10 compilers", or the "Compiling programs -text".