Install Xcode 5
The download/install takes a while so start it first. When it finishes downloading you will still need to run it to complete installation.
Note: Make sure you install the XCode Command Line Tools after XCode is done installing. To do this go to Xcodes -> Preferences -> Downloads -> Command Line Tools -> Install. If you don't you might not be able to install brew packages (i.e. brew install wget will fail).
ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"
Note that Xcode is a pre-req for Homebrew
curl -L https://github.com/robbyrussell/oh-my-zsh/raw/master/tools/install.sh | sh
restart terminal
brew install git
http://help.github.com/mac-set-up-git/
Copy over your SSH Keys from your existing machine if you have them and want to carry over your existing SSH configs.
\curl -sSL https://get.rvm.io | bash -s stable
source /Users/username/.rvm/scripts/rvm
Start new shell session
You need to provide the --with-gcc=clang flag because of LLVM issues, else 1.9.3 will not work fix per [this StackOverflow](http:///stackoverflow.com/questions/8032824/cant-install-ruby-under-lion-with-rvm-gcc-issues)
rvm install 1.9.3 --with-gcc=clang
rvm install 1.8.7
rvm notes
See if there is anything in the rvm notes you need to take action on. As of this writing the compiler needs to be overridden.
Create a ~/.gemrc file and add the line
gem: --no-ri --no-rdoc
rvm --default 1.8.7
rvmsudo gem install bundler
rvmsudo gem install lunchy
curl https://raw.githubusercontent.com/creationix/nvm/v0.7.0/install.sh | sh
curl http://npmjs.org/install.sh | sh