I think Java/JDK was closed source initially, then went open source in 2006/2007 (?), but without the TCK. The TCK was never open sourced but the JCK is now kin

I think Java/JDK was closed source initially, then went open source in 2006/2007 (?), but without the TCK. The TCK was never open sourced but the JCK is now kind of "open": https://openjdk.org/groups/conformance/JckAccess/ https://openjdk.org/groups/conformance/JckAccess/