Zulu is described as 'The only certified multi-platform build of OpenJDK : Free, 100% open source Java for Windows, Linux (including Docker), Mac OS X, the Cloud and embedded applications. Featuring tier-one Java support via Zulu Enterprise' and is an app in the Development category. There are six alternatives to Zulu for Linux, Windows, Mac and BSD. The best alternative is OpenJDK, which is both free and Open Source. Other great apps like Zulu are Adoptium (Free, Open Source), Liberica JDK (Free, Open Source), Microsoft OpenJDK (Free, Open Source) and Amazon Corretto (Free, Open Source).
The code for Java is open source and available at OpenJDK™. Adoptium provides prebuilt OpenJDK binaries from a fully open-source set of build scripts and infrastructure.
Get Docker Images on Docker Hub. Nightlies can be found in the Archive.