Differences between JVM implementations

Question

Where do JVM Implementations differ (except licensing)? Does every JVM implement Type Erasure for the Generic handling?

Where are the differences between:

Answer 1

Another difference between JVMs is behaviour on undocumented API. (e.g. com.sun.xxx) For example, Sun's JVM and IBM's JVM both have slightly different behaviour on signal handling. (IBM's JVM doesn't allow the application to trap the "INT" signal in certain cases.)