A couple of weeks ago I decided to backup my hard drive, reformat it and reinstall OS X Mavericks to get rid of the cruft that seems to have built up in 4 years, updating from every OS since Mac OS X 10.5 Leopard.
I made halfhearted attempts to organize my dotfiles and configuration in the past, like the cool kids do on Github. That’s when I learned about Homebrew Cask (http://caskroom.io) which makes it super easy to install the GUI apps I install on whatever Mac I’m using—iTerm, Transmission, Vagrant, Virtual Box, etc.
And now I have them in a Brewfile (http://robots.thoughtbot.com/brewfile-a-gemfile-but-for-home...) under version control in case I need to install the whole shebang on another Mac.
And now brew update && brew upgrade updates everything.