Zulu is simple: It is a free and freely re-distributable binary distribution of OpenJDK for Linux, Windows, and Mac OS. Each binary is tested and certified (literally), which in the Java world is no small thing.

For MacOS and Windows, Zulu is the only binary distro of OpenJDK that I am aware of. For Linux (as of this writing), Zulu is the only publicly available binary distro of OpenJDK 8 that actually undergoes TCK testing and Java SE compatibility testing. [RedHat provides 7 and 6 binaries through the IcedTea project, but IcedTea has not yet shipped a Java 8 version].

So unless you want to build OpenJDK from source (and test top verify what you built is good), you'll need to get a binary from somewhere. Zulu is that somewhere.

To demonstrate the simple value of a tested and certified binary build: The current default Java binary thing you get on docker's official Java runtime image for Java 8 is 8u40 (https://registry.hub.docker.com/_/java/). But 8u40 doesn't actually exist. It is still in development in OpneJDK and won't be released until March 2015. So this thing you pull off a repo is certainly not a tested or released version (likely a top of tree snapshot built from source and just pushed to an experimental repo).

For a current list of companies and organizations that are actually able to fully test OpenJDK 8 (or 7, or 6), see the TCK signatories list at: http://openjdk.java.net/groups/conformance/JckAccess/jck-acc...

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