Ruby
brew install rbenv ruby-build
echo 'if which rbenv > /dev/null; then eval "$(rbenv init -)"; fi' >> ~/.bash_profile
source ~/.bash_profile
rbenv install -l
rbenv install 2.3.1
rbenv global 2.3.1
rbenv local 2.3.1
gem install bundler

PostgreSQL
brew install postgresql
ln -sfv /usr/local/Cellar/postgresql/*/*.plist ~/Library/LaunchAgents/
launchctl load -w ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist

Redis
brew install redis
ln -sfv /usr/local/opt/redis/*.plist ~/Library/LaunchAgents
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.redis.plist

MySQL
brew install mysql
ln -sfv /usr/local/opt/mysql/*.plist ~/Library/LaunchAgents
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

MongoDB
brew install mongodb
ln -sfv /usr/local/opt/mongodb/*.plist ~/Library/LaunchAgents
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.mongodb.plist