[heisenbit]

Well, Java during its initial life was controlled to a degree through the control of the tests: https://en.wikipedia.org/wiki/Technology_Compatibility_Kit .

[vitiral]

Huh, I wasn't aware that Java was initially open source

[karussell]

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/