OpenJDK is also made (primarily) by Oracle [1]; in fact, OpenJDK is the name of Oracle's one and only Java implementation project, although Oracle builds both free and support subscription binaries from it. Both OpenJDK and Graal are open source, though. OpenJDK now includes a tool called jlink [2] that allows you to create a small, self-contained bundle that includes a custom runtime as well as your app.

[1]: http://openjdk.java.net/

[2]: https://docs.oracle.com/en/java/javase/13/docs/specs/man/jli...