The Ipopt Plugin is a driver for the Ipopt optimizer ( http://www.coin-or.org/Ipopt/ ) which is a software package for large-scale nonlinear optimization. In addition to the requirement of having Ipopt installed, the Python wrapper, Pyipopt ( https://github.com/xuy/pyipopt/ ) needs to be installed. To view the Sphinx documentation for this distribution, which includes information on how to make use of the wrapper, type: openmdao docs ipoptdriver