Clojure Contrib is a collection of libraries managed with the same Contributor Agreement, license, and development workflow as Clojure itself. Code in Clojure Contrib can be considered for inclusion in newer versions of Clojure.
Prior to Clojure 1.3, Contrib was packaged as a single monolithic JAR. If you are migrating from a pre-1.3 version of Clojure, please see this page for migration help regarding old contrib libraries.
The vast majority of Clojure developers use Leiningen to create and manage Clojure projects.
Community volunteers maintain Getting Started documentation for a number of different developer tools.