Macro or not to macro? (here, via @panetclojure) -- In the rare case that you need to write a macro, this article provides some common sense about writing them (mainly, consider the user of such macro).
TDD in Clojure: Mocking & Stubbing (here, via @jneira) -- A short and sweet article on how to use clojure.contrib.mock
SICP Chapter 4.5 - Art of the Propagator (here, via @planetclojure) -- David Nolen found a paper that could be chapter 4.5 of Structure and Interpretation of Computer Programs. From the referenced paper by one of the authors of SICP: "This model makes it easy to smoothly combine expression-oriented and constraint-based programming; it also easily accommodates implicit incremental distributed search in ordinary programs"
ref-set vs commute vs alter: What is the difference in the 3 ways to set the value of a ref in Clojure? (here, via @stackoverflow) -- Because sometimes it is good that somebody reminds us every now and then that you can update a ref in clojure in 3 different ways....