As long as OpenJDK remains open and maintained for a reasonable length of time, I don't mind. Right now it's looking good, but only thanks to Red Hat (et al.) and not Oracle.
When did Red-Hat hired all Oracle developers working on OpenJDK?
They have quite a few developers working on OpenJDK
Yes they do, but the large majority are Oracle employees, which many seem to keep forgetting.
So many companies have a vested interest in maintaining Java alive (Google, IBM, etc.) that I'm not too worried about maintenance of OpenJDK.
Oracle can easily stop or delay updates to OpenJDK if they want. Remember how things worked out for OpenSolaris?
OpenJDK used to have some incompatibilities that tended to blow up in production (rare case "enjoyment") - is it now 100% compatible with original Oracle SDK? Otherwise companies would be forced to use commercial one in order not to disrupt their legacy systems.
Not 100%. There's still some weird edge cases having to do with the swing and crypto libraries. But the big performance regressions that we used to see are gone and with the release of flight recorder in Java 11, the last major commercial feature is now in openJDK.
Legacy is most of Oracle's business model nowadays
I've found that as of Java 8 the compatibility is pretty good, and I use OpenJDK exclusively now. Prior to that, it definitely had issues and I always used the Sun/Oracle JDK.
In addition to compat, is performance on par too? I know the JVM is highly performant and was wondering if there were any patent restrictions that would prevent an open JRE (I assume there is such a thing) from being as performant as the Oracle JRE.
I'm sure all the Linux distros are thinking the same thought.
The 'default' JVM for Ubuntu is OpenJDK, right? You'd have to go out of your way to get your hands on Oracle JDK.
Yes. Back in jdk6 days there were more problems requiring oracle jdk, this days is a no brainer to use the default openjdk.
Agreed, it's what I've been using in production all along and maybe the rise of docker will mean that fewer people are directly installing the JDK on their production machines. Still, I bet there will still be some unfortunate souls that run the Oracle JDK in production without knowing the rules have changed.