There were some subtractions for a bunch of stuff that wasn't getting much love to begin with. They removed their JS interpreter which was based on rhino which continued being a side library the entire time that java added it to the Java runtime. The only personal break that had no remediation was a minor helper class in JMX that affected me. Pretty much anything that was removed has some library addition that can add back what was cut. Basically Java 6-8 added a bunch of library support things that were probably better maintained as a third party library to begin with. The module system usually means adding some security policy exclusions for popular libraries, but in general I get a very well performing JVM that feels like it optimizes the code significantly better than in previous generations.