The Fortran subroutine NLPQLP, a newer[when?]
version of NLPQL, solves smooth nonlinear programming problems by a sequential quadratic programming (SQP) algorithm.
The new version is specifically tuned to run under distributed systems.
In case of computational errors, such as inaccurate function or gradient evaluations, a non-monotone line search is activated.
The code is easily transformed to C by f2c and is widely used in academia and industry.