- Install Java
- Get Nightcode installed
- Test installation
Go to Oracle Java Development Kit (JDK) 8 download site. You should see a screen with various download options. Accept the license agreement and select Mac OS X:
Nightcode is a Clojure IDE (Integrated Development Environment, which means that it is a text editor, like Word, only specialized for writing programs) that comes bundled with other tools useful for working with Clojure.
To download and install Nightcode, go to https://sekao.net/nightcode/.
Scroll down to "Download version 2.3.2" (the version number may be different), click on the Jar icon: 
Once it downloads, you might want to drag it into your Programs folder or any other place where it would be convenient to access it later (you also might want to create a folder for Clojure work and put it there).
After you move it, double-click on it to start.
You may get a message indicating that this type of files may be harmful for your computer and asking you if you still would like to run it. Allow running it. If you get a message that the firewall has blocked some of its features, click "allow access".
Once Nightcode is successfully installed, it will start and look like the picture above (only without all the code).
Now follow to instructions for your track to get the Clojure project you will be working on: