nced scalability</h2>
Version 6.0 of the collector adds two facilities to enhance collector
scalability on multiprocessors.  As of 6.0alpha1, these are supported 
only under Linux on X86 and IA64 processors, though ports to other
otherwise supported Pthreads platforms should be straightforward.
They are intended to be used together.
<UL>
<LI>
Building the collector with <TT>-DPARALLEL_MARK</tt> allows the collector to
run the mark phase in parallel in multiple threads, and thus on multiple
processors.  The 