MM5, which superseded its predecessor MM4, was released to the public in the early 1990s. MM5 and its supporting software (i.e, pre-processing and post-processing programs) were originally designed to run on a Cray supercomputer. Over the past few years, the software structure has been modified to enable the model to also run on various workstations. Today, MM5 can run on many hardware platforms including Cray, SGI, Sun, DEC, Hewlett Packard, IBM, and personal computers running Linux. In addition, MM5 has software directives to efficiently use multi-processor computers, including shared-memory, distributed-memory, and massively parallel architectures. Although MM5 has been run on workstations, not all of the supporting software is available in a workstation version at this time. Also, there may be significant performance differences when running MM5 on different manufacturers’ workstations and supercomputers.

CMAQ Version 4.4 does not include MM5. Users will need to download and install MM5 on their own.