Before you can use there are a couple of thing you need to do.
Obviously you need to install Haxe. There are a couple of ways to do it, but in this document I will send you to the official Haxe place and official Python place.
And a code editor will be useful!
Current Haxe version is (at the time of writing):
But if the version numbers changed, it means I haven’t updated this part of the document in some time :D

Haxe only works with Python 3, so you need to install python 3.
Or use your favorite OSX installer:
brew install python3
You can find a extensive list on http://haxe.org/. And even a bigger list on the old website…
(And I see no mentioning of Atom and Brackets…. even more choices)
But to keep everything simple
Install FlashDevelop
Install Visual Studio Code with the Haxe Extension Pack .
Install Sublimetext 2 with the haxe sublime2 bundle.
It’s freakish difficult to setup a project, but after that AWESOME! IntelliJ IDEA with Haxe support plugin
Read more about code editors here