Clojure's fully functional paradigm is a big shift for many people, including myself. My experience with functional languages comes from OCaml in university, and programming along SICP using Scheme/Racket. What are some good open-source Clojure projects that I could study to learn common idioms, techniques, and how larger projects are actually structured?
Am I wrong or does Clojure use functional elements but is not a "fully" (i.e. pure) functional language (same with Lisp)?
Niether Clojure or Lisp are pure functional programming languages, not like Haskell any way.
As for the original poster, Github hosts tons of Clojure project. I'm pretty sure you will get some projects that you will like and learn a lot from them.
This comes up fairly often on the Clojure mailing list and the consensus seems to be that the Clojars project is a fairly good example to look at.
Toby's pointer to github projects written in Clojure is a good general place to start but I suspect most "real-life" Clojure code, at an application level, is behind corporate firewalls right now with only the libraries out in public. I'm hoping to open source some of the Clojure code that my company is creating but it may be a while before that happens (and, to be honest, much of that would really only be higher-level libraries built around other stuff).
It may just be too early in Clojure's cycle for a substantial amount of open source _application_ code.