OpenJDK
OpenJDK is the open reference implementation of Java SE, including the JVM, compiler, standard library, and cross-platform runtime.
Why use it
Java game frameworks, build tools, and online services benefit from mature monitoring, concurrency, and libraries.
Where it fits
Find engines, frameworks, code libraries, version control, and production automation.
What to check
Standardize distributions, support windows, and deployment terms, and load-test garbage-collection pauses.