1. System Software Update.
  2. Download and install Xcode, or Command Line Tools for Xcode only if you don’t need Xcode.
  3. Install Homebrew.
  4. Get back your dotfiles if you have.

## Python

  1. Use pip instead of easy_install
  2. Use pip to install virtualenv and virtualenvwrapper
# use easy_install to install pip
sudo easy_install pip
# where pip
/usr/local/bin/pip
# virtualenv
sudo pip install virtualenv
# which virtualenv
/usr/local/bin/virtualenv
# virtualenvwrapper
sudo pip install virtualenvwrapper
# virtualenvwrapper will be installed in /usr/local/bin/virtualenvwrapper.sh
# config virtualenvwrapper
mkdir ~/.virtualenvs
# edit .zshrc and add
export WORKON_HOME=$HOME/.virtualenvs
source /usr/local/bin/virtualenvwrapper.sh

## Ruby

Install RVM

# add to .zshrc
[[ -s $HOME/.rvm/scripts/rvm ]] && source $HOME/.rvm/scripts/rvm
# install ruby by rvm
rvm install 1.9.2 && rvm use 1.9.2
rvm rubygems latest