Standard interface across platforms

One of the main strengths of the BLACS is that code which uses the BLACS for its communication layer can run unchanged on any supported platform. There are various packages designed to provide a message passing interface that remains unchanged on several platforms, including PICL, and more recently, MPI. These packages are not available on all of the platforms that we wish to use. More importantly, they are attempts at general libraries, and are thus somewhat harder to use than a more restricted code.

The BLACS are written specifically for linear algebra programming. Since the audience of the BLACS is known, the interface and methods of using the routines can be simpler than for those of more general message passing layers.

The BLACS have been written on top of the following message passing layers:

CMMD: Allows the BLACS to run on Thinking Machine's CM-5.
MPI: Allows the BLACS to run across most parallel platforms.
MPL: Allows the BLACS to run on IBM's SP series (SP1 and SP2).
NX: Allows the BLACS to run on Intel's supercomputer series (iPSC2, iPSC/860, DELTA and PARAGON).
PVM: Allows the BLACS to run anywhere PVM is supported, which includes most UNIX systems.

The BLACS are freely available, and can be downloaded from here.