It's been a few days since [Erlang/OTP 17.0](http://www.erlang.org/news/73) has been released. Installing 64 Bit Erlang (with [Observer](http://www.erlang.org/doc/man/observer.html) support) on Mac OS X has always been a bit tricky, but with 17.0 it has gotten significantly easier.
First you need to install/get some prerequisites:
* [Command Line Tools for Xcode](https://developer.apple.com/downloads) or [Xcode](http://itunes.apple.com/us/app/xcode/id497799835)
* [Homebrew](http://brew.sh)
* [kerl](https://github.com/spawngrid/kerl)
After you've gotten these three, we start by installing *wxWidgets*. It's required in order to use the Observer GUI.
{% highlight bash %}
brew install wxmac
{% endhighlight %}
Compiling *wxWidgets* might take some time. After it's done, you should create a `~/.kerlrc` file. It's basically a configuration file for *kerl*, which will be used for every Erlang version you compile. You can find the list of available options in the [*kerl* readme](https://github.com/spawngrid/kerl#tuning). Mine looks like this:
We can now move on to actually installing Erlang/OTP 17.0.
{% highlight bash %}
kerl update releases
kerl build 17.0 17.0
kerl install 17.0 17.0
{% endhighlight %}
After the installation is finished, *kerl* will output instructions on how to enable a specific Erlang version globally. In general, you will put something like the following in your `~/.zshrc` or `~/.bash_profile`:
{% highlight bash %}
source $HOME/.kerl/installs/17.0/activate
{% endhighlight %}
The following `alias` makes it easier to start the Observer from a terminal. The only command you have to remember is `erlobserver`.
{% highlight bash %}
alias erlobserver='erl -sname observer -run observer -detached'
