# 1. Getting Started¶

Getting started in O is easy! Just follow the steps below and you’ll be ready to go!

## 1.1. Getting the interpreter¶

You can download latest release from http://github.com/phase/o/releases or clone the repository and compile it manually:

git clone https://github.com/phase/o && cd o
make all
./o


Running the executable without any arguments will open the REPL, which you can type lines of O code into to have them interpreted.

You can also go to http://o-lang.herokuapp.com and use the always-updated-interpreter so you won’t have to recompile every update.

## 1.2. Let’s test it out!¶

Whether you’re on the online IDE or using the REPL, this Hello World program will run on both:

"Hello, World!"o


This is the simplest Hello World program in O. It pushes the string Hello, World! to the stack and outputs it with o. You will learn about why the o isn’t needed in the next section.