These notes are based on Patrick O'Leary's video that he kindly created when I was wingeing about problems with git. It is best to watch the video first then go back through these notes to recall the steps.
Create a clone of the JuliaLang repository
git clone git://github.com/JuliaLang/julia.git
or
git clone git://github.com/JuliaLang/julia.git myjulia