Mix is a build tool that allows you to easily create projects, manage tasks, run tests and more:

$ mix new my_app
$ cd my_app
$ mix test
.

Finished in 0.04 seconds (0.04s on load, 0.00s on tests)
1 tests, 0 failures

Mix is also able to manage dependencies and integrates nicely with the Hex package manager, which provides dependency resolution and the ability to remotely fetch packages.

IEx (Elixir’s interactive shell) is able to leverage many aspects of the language and platform:

$ iex
Interactive Elixir - press Ctrl+C to exit (type h() ENTER for help)
iex> c "my_file.ex"        # Compiles a file
iex> t Enum                # Prints types defined in the module Enum
iex> h IEx.pry             # Prints the documentation for IEx pry functionality

Elixir runs on the Erlang VM and programmer can invoke any Erlang function with no runtime cost:

iex> :crypto.md5("Using crypto from Erlang OTP")
<<192,223,75,115,...>>