# Dependence on other software

The current implementation of PeIGS communicates among processes using the TCGMSG portable message passing library, except on Intel machines where it uses the native NX message passing library. PeIGS can use MPI, when available, in place of TCGMSG and Intel NX.

PeIGS also uses a number of BLAS and LAPACK routines which are available via anonymous ftp from netlib.att.com. All of the required BLAS and LAPACK routines are also supplied in the PeIGS distribution.