[kaba0]

There are barely any breaking changes, I could still run a graphical application written by a prof in early 2000s, served on his website as a jar. No other language comes remotely as close to this level of stability.

As for the changes in 8->9, there was a stagnation period in the last year of Sun, and many people overfitted their libs to 8, by e.g. making use of internal APIs made accessible through reflection. This was never a good idea, and all that is happening now is that you have to explicitly state at invocation what kinds of non-future-proof modules you make use of, so that you are made aware of what could potentially change, plus it disincentivizes libraries from accessing these non-public APIs.