Server-class machine ergonomics was introduced in jdk5. If the machine upon which
the jvm is running is powerful enough (currently, at least 2 physical cores plus
at least 2gb of memory), the server jvm is invoked using the parallel scavenger
rather than the serial scavenger. Currently the old gen collector used is
serial mark-sweep-compact. Now that the parallel old gen collector is mature,
we should change to using it instead.