The Linux Kernel interface does an excellent job of remaining stable. There&#x27;s a surprisingly small set of interfaces that the kernel actually exposes to userland, and in the words of Linus, &quot;WE DO NOT BREAK USERSPACE!&quot;.<p>I don&#x27;t see the lack of stable APIs elsewhere as an actual problem. The biggest problem is that it makes life harder for proprietary software developers - it&#x27;s pretty much mandatory for them to setup automated CI &amp; release processes if they want their software to actually be usable.<p>There&#x27;s a huge upside to not caring about a huge stable userspace API: it&#x27;s much easier to continue to evolve if you just stop caring about backwards compatibility. And often, backwards compatibility means giving up your future to hold on to your past. The difficulty of getting <i>anything</i> done grows exponentially more complicated, often with few significant tangible benefits.