The IMSL Fortran Numerical Library allows users to leverage the high-performance technology of shared memory parallelism (SMP) when their environment supports it. Support for SMP systems within the IMSL Library is delivered through various means, depending upon the availability of technologies such as OpenMP, high performance LAPACK and BLAS, and hardware-specific IMSL algorithms. Use of the IMSL Fortran Numerical Library on SMP systems can be achieved by using the appropriate link environment variable when building your application. Details on the available link environment variables for your installation of the IMSL Fortran Numerical Library can be found in the online README file of the product distribution.

The IMSL Fortran Numerical Library is thread-safe in those environments that support OpenMP. This was achieved by using OpenMP directives that define global variables located in the code so they are private to the individual threads. Thread safety allows users to create instances of routines running on multiple threads and to include any routine in the IMSL Fortran Numerical Library in these threads.