Erlang
sudo apt-get install erlang
Elixir
wget https://packages.erlang-solutions.com/erlang-solutions_1.0_all.deb && sudo dpkg -i erlang-solutions_1.0_all.deb
sudo apt-get update
sudo apt-get install elixir
Phoenix
mix archive.install https://github.com/phoenixframework/archives/raw/master/phoenix_new.ez
Erlang Donwload here
Remember to choose the OSX tab
Elixir
brew update
brew install elixir
Phoenix
mix archive.install https://github.com/phoenixframework/archives/raw/master/phx_new.ez
sorry the little delay @amalbuquerque, updated