    -Xbootclasspath:<directories and zip/jar files separated by :>
                      set search path for bootstrap classes and resources
    -Xfuture          enable strictest checks, anticipating future default
    -Xgc:compacting   use the compacting garbage collector
    -Xgc:copying      use the copying garbage collector
    -Xglobal<size>    set maximum global region size	
    -Xms<size>        set initial Java heap size
    -Xmx<size>        set maximum Java heap size
    -Xmp<percentage>  set new space goal (for compacting collector)
    -Xss<size>        set maximum stack size for any thread
    -XO               do not generate stack trace information for exceptions

The -X options are non-standard and subject to change without notice.