There are just a few requirements for this workshop:
java -version
in a command line windowlein version
in a command line windowSee the section on Development Environments for Clojure for more options
You may notice that there is no actual Clojure installation. Clojure is a library that is added to the project, just like any other dependency (ie. in Maven, Gradle, etc).
The Clojure library is very small and Leiningen caches it and oll other libraries locally in the same folder structure that Maven uses, eg
~/.m2/repository/