BLACS (Basic Linear Algebra Communication Subprograms) <description><url>http://www.cs.utk.edu/~rwhaley/Blacs.html</url> The BLACS (Basic Linear Algebra Communication Subprograms) project is an ongoing investigation whose purpose is to create a linear algebra oriented message passing interface that may be implemented efficiently and uniformly across a large range of distributed memory platforms. The length of time required to implement efficient distributed memory algorithms makes it impractical to rewrite programs for every new parallel machine. The BLACS exist in order to make linear algebra applications both easier to program and more portable. It is for this reason that the BLACS are used as the communication layer of ScaLAPACK. 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. 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. <keywords>high level communications library; linear algebra; message passing <category>ppt-comm <contact>blacs@cs.utk.edu <environment> 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. 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. </urc>