The response by Brian Goetz[1] is kind of unpleasant and combative. Moreover, the ideas in it kind of encapsulate why I'm growing more and more uncomfortable with relying on the JVM to keep up with my needs in the future.<p><i>> The cost of the C# approach is that existing
classes could not be gradually migrated to be generic; existing collections had to be effectively deprecated and replaced, or a "flag day" had to be declared where all the code (library and client) changes simultaneously. These are not options for us.</i><p>This is why, despite doing it in my day job, I'm not high on the JVM's future as it stands right now. Compatibility uber alles is <i>not</i> a virtue, even Microsoft gets that these days. Saying "on 1 Jan 2017 we're pushing Java 10, and you will need to recompile your dependencies to upgrade" is not a bad thing. No, many people won't upgrade immediately. That's true. But <i>they already don't</i>! It takes years for consumers to catch up with the newest version of Java (for reasons that do not reflect well on those consumers). Why should I, as a consumer, care about them? Why should I, as a consumer, continue to use your product when you would care about laggards more than me? I mean, Oracle's welcome to, it's their business, but why would I respond positively to that?<p>But he says that a flag day means they "hate their users." No, it would mean they are going to firewall off the damage laggards can do to their environment and ecosystem. And for the sake of a healthy platform for the next decade I would think they should do exactly that, because those laggards don't make the ecosystem and the environment better.<p>And then, at the very end:<p>> And, feel free to prove us wrong! Try implementing the changes you are envisioning in the JVM, and show how they can get us to the goal!<p>Why should I, guy-who-works-for-Oracle? I'm not drawing a paycheck from Oracle, who owns Java so utterly and wants to attack and damage related tools and platforms (hi, Android), and guess what? I really don't need Oracle to fix this because in 2015 I am going to have <i>options</i>. Microsoft is releasing an open-source CLR for OS X and Linux and it's effectively substitutable for just about anything I care to use (and, if I had to be honest, a combination of C# and F# are probably better than even Scala for what I do). This is <i>Oracle's</i> problem and Oracle's ground to lose, not mine.<p>Two-thirds of my Github are C# and Ruby at this point, anyway, and I don't even use C# for work.<p>[1] - <a href="http://mail.openjdk.java.net/pipermail/valhalla-dev/2014-December/000475.html" rel="nofollow">http://mail.openjdk.java.net/pipermail/valhalla-dev/2014-Dec...</a>