OpenJDK is the name of an open source implementation of Java. It started as an open sourcing of part of the codebase to Sun's JDK, and gradually more parts move

OpenJDK is the name of an open source implementation of Java. It started as an open sourcing of part of the codebase to Sun's JDK, and gradually more parts moved from the closed source portions to the open source ones (i.e. OpenJDK). Sometimes, some closed source, commercial features were added, but as of JDK 11, Oracle completed open sourcing the entire JDK -- that's OpenJDK. IBM still have their own VM, J9, and while they produces JDK builds that they misleadingly call OpenJDK, they are not. They replace the OpenJDK JVM (HotSpot) with theirs, but keep the standard libraries. So it's not OpenJDK, but it's a JDK that uses most of the OpenJDK standard libraries. Azul have two JDKs. They have the proprietary Zing, which uses their own VM (which, in turn, is a modification of HotSpot, which they licensed, with their own optimizing compiler and GC) and the OpenJDK libraries, and the open source Zulu, which is an OpenJDK build. I think IcedTea is also an OpenJDK build. > What the hell is this thing: https://hub.docker.com/_/openjdk https://hub.docker.com/_/openjdk Is that Oracle's OpenJDK release, which is different from Oracle Java? Or is this the IceTea release? Good question.