How to install Zulu java from azulsystems as an alternative to OpenJDK.

OpenJDK is sometimes slightly behind the official Oracle releases as well as that OpenJDK doesn't provide all the Java versions for all OS'es. (For instance Java 12 isn't available from repo on Ubuntu 16 but only on Ubuntu 18)

Simplest way to install is via repository. Procedure described here is for Ubuntu but for other flavors of Linux the procedures are here:

Adding the repo

Import Public Key
apt-key adv --keyserver hkp:// --recv-keys 0xB1998361219BD9C9
Add the actual repository
apt-add-repository 'deb stable main'

Update the cache for all packages
apt-get update
apt update


Actual installation of packages
apt install zulu-{version number}
or apt-get install zulu-{version number}