Install XCode from the App Store.

Install the XCode command line tools from the 'Downloads' pane in XCode.

Install SublimeText.

Install SublimeText Package Control.

Install Sublime Linter.

Installing Homebrew:

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

Follow Homebrew setup instructions.

Install Python with Homebrew:

brew install python --framework

Install common Unix packages using Homebrew:

brew install screen wget mc bash-completion gnupg graphicsmagick links readline git node tidy-html5 xmllint

Install HTML5-tidy linter (see https://github.com/Homebrew/homebrew-dupes/pull/150):

brew install --HEAD tidy

Some additional changes to ~/.bash_profile:

# Homebrew over local packages (should only occur once)
PATH="/usr/local/bin:$PATH"

# --- Make PIP faster
# Use mirrors when central package repository is down
PIP_USE_MIRRORS=true

# Use crate.io for the package index export
PIP_INDEX_URL=https://simple.crate.io/

# Cache previously downloaded packages locally
PIP_DOWNLOAD_CACHE=~/.pip/download_cache

# Export to make these available in your working environment
export PIP_USE_MIRRORS PIP_INDEX_URL PIP_DOWNLOAD_CACHE

# --- Homebrew bash completion
if [ -f $(brew --prefix)/etc/bash_completion ]; then
        . $(brew --prefix)/etc/bash_completion
fi

# PIP command line completion
eval "`pip completion --bash`"

# SublimeText 2 as default editor (optional)
export EDITOR='subl -w'

# Node binaries
export PATH="/usr/local/share/npm/bin:$PATH"

# Set nice colors for terminal (optional)
export PS1='\[\033[01;32m\]\u@\h\[\033[01;34m\] \w \$\[\033[00m\] '

Install Python packages:

pip install virtualenv ipython Pillow pep8 ipdb South Django Fabric Pygments mercurial surlex sorl-thumbnail readline raven nose lxml gunicorn coverage django-extensions beautifulsoup4 six selenium Sphinx PyYAML docutils WebTest

Install Node.js packages:

npm install -g jshint require grunt

Install Ruby packages:

gem update --system
gem install compass