Zing and Zulu are not the same. Zing is a commercial JVM that has no open source equivalent, and has a completely bespoke design from my understanding -- calling Zing a "modified openjdk" is a stretch, from what I understand (especially considering OpenJDK is GPLv2.)
Zulu is Azul's build of open-source OpenJDK, and no different than any other OpenJDK such as one from jdk.net or AdoptOpenJDK -- it doesn't have a special JIT or special GC, but you can buy a support contract for Zulu (or use it at no cost). It's basically just another OpenJDK build, as far as most people are concerned.
I was talking about Zing, yes. The parent said Zulu and I din't want to go into details. And yeah... it is more than a modified openjdk, I think we can agree and say it is based on openjdk.
Zulu is Azul's build of open-source OpenJDK, and no different than any other OpenJDK such as one from jdk.net or AdoptOpenJDK -- it doesn't have a special JIT or special GC, but you can buy a support contract for Zulu (or use it at no cost). It's basically just another OpenJDK build, as far as most people are concerned.