Install latest XCode via App Store and Command Line Tools Xcode -> Preferences-> Downloads install Command Line Tools

ruby -e "$(curl -fsSL https://raw.github.com/mxcl/homebrew/go)"

brew install node

curl https://npmjs.org/install.sh | sh

After cloning the repo, run npm install to install development dependencies. From there, run grunt to start a local server or grunt start to start a server and open your browser to it. Handy!