[<< wikibooks] Erlang Programming/Getting Started
== Getting Erlang ==
Erlang/OTP is available as free software from Open Source Erlang Downloads. Once you have downloaded the Erlang/OTP distribution, you will need to compile it (if on a Unix platform) and install it.

== Installing Erlang ==
In addition to the brief instructions below, you may wish to consult the Installation Guide.

=== Unix ===
Unpack the source distribution. Decide where you want Erlang and its libraries installed. For our example, we will assume you want it in /usr/local/erlang/otp_r11b. Create this directory, as well as a build directory for building the Erlang sources.

mkdir /usr/local/erlang/otp_r11b

From within the top-level directory, type ./Install /usr/local/erlang/otp_r11b. This will configure, build and install the Erlang/OTP distribution.
Add the distribution's bin directory to your path. You may wish to set this in your shell initialization file.

=== Microsoft Windows ===
The distribution is a self-installing .exe file. Invoke it (for example, by double-clicking on its icon) and answer the prompts.

== The Erlang Shell ==
Erlang comes with a shell which is used interactively when controlling the Erlang environment and developing programs. On Unix, invoke the shell by typing erl on the command line. On Windows, type werl on the command line, or double-click the Erlang shortcut icon.
This starts the Erlang system and provides a shell for input and evaluation of Erlang.

Eshell V5.4.13 (abort with ^G)

== Your First Erlang Code ==
At the shell prompt, type "hello, world!" followed by a dot (.). You can follow that up with some arithmetic. Or answer the question "What is six times 9?" in base-13 notation:

1> "hello, world!".
"hello, world!"
2> 1 + 2.
3> 13#6 * 13#9.

When you are ready to exit, you can stop the Erlang system using the halt() built-in function:

4> halt().