This technique takes advantage of Platform MXBeans available since J2SE 5 (custom MXBeans support was added in Java SE 6).
Two useful sources of information on the JVM parameters available when using Sun's JVM are:
- A Collection of JVM Options and
- Charles Nutter's Favorite Hotspot JVM Flags.
Both of these resources list and describe some/all of the not-recommended-for-the-casual-developer double X arguments (-XX) that are available.