When Oracle announced that it would no longer be allowed to run their Oracle Java SE JDK on production without paying for it for releases after the 1st of January 2019, we wanted to support another JDK to give our customers a choice if they want to pay or use a free JDK.

Support for more (open)JDK brands increases our test efforts exponentially. During development we encountered code that detects the JDK you are running and therefor might break using other JDK builds.

Why we chose the current supported JDK's

• Technology Compatibility Kit validated: companies that can do this: http://openjdk.java.net/groups/conformance/JckAccess/jck-access.html
  • AdoptOpenJDK for example does not have this.
• Both LTS and non-LTS releases
  • Amazon Corretto for example only does LTS releases
• (optional) can get paid support if needed
  • Oracle OpenJDK does not have this option
• Generic platform support
  • RedHat build of OpenJDK officially only supports Redhat Enterprise Linux and Windows https://access.redhat.com/articles/1299013?extIdCarryOver=true&sc_cid=701f2000001OH6kAAG#OpenJDK_Lifecycle_Dates_and_RHEL_versions, we want to have the option to support other linux versions

Feature/JDK	Oracle JDK	Azul Zulu
Original Developer	(after buying Sun Microsystems)
TCK Validated
Free version	OpenJDK
LTS support
non-LTS support	(no extended support available)
Commercial support		(in place upgrade to Zulu enterprise)
Platform Support	Windows, Linux, macOS, Solaris	Windows, Linux, macOS, Solaris

Differences between OpenJDK builds

Although all OpenJDK derived builds are in build from the same source code they might be different based on parameters or added components. For example the Shenandoah GC is included in some openJDK builds from JDK 8, but is missing in the Oracle Java SE JDK.