This book describes how to use the Sun-specific extensions and features included with the Sun Performance Library routines. The Sun Performance Library is a set of optimized, high-speed mathematical subroutines that are used to solve linear algebra problems and other numerically intensive problems. This book also discusses using the C, FORTRAN 77, and Fortran 95 32-bit and 64-bit Sun Performance Library interfaces, compiling code for 64-bit enabled Solaris[tm] operating environments, optimizing code for parallel processing, and using the sparse solver package, which is a collection of routines used to factor and solve sparse linear systems of equations.