Before installing Kotlin, we need to have JDK installed, as Kotlin relies on JDK.

In this course, we will be using OpenJDK. OpenJDK can be downloaded from http://jdk.java.net/. Alternatively, we can use Oracle JDK, which can be downloaded from http://www.oracle.com/technetwork/java/javase/downloads/index.html.

After installing the JDK, set the PATH variable to include the JDK installed and we can check its version using the java --version command.

Once we have JDK installed, we need to set up Kotlin. We will look at how to install it in the following section.