Last week Wolfram announced the launch of its Parallel Computing Toolkit 2.1. From the story at HPCwire
Following strong demand from the high-performance-computing community for Mathematica 6, Wolfram Research today launched Parallel Computing Toolkit 2.1 — an optimized parallel solution for anyone with access to Mathematica and more than one processor.
…Parallel Computing Toolkit is available for Windows NT/2000/XP/Vista, Mac OS X, Linux x86/Itanium, Solaris UltraSPARC/x86, HP-UX, IBM AIX, and compatible systems, and requires at least one Mathematica 6 process for the master control. Remote kernel processes require Mathematica 5.2 or later.