Several new interfaces have recently been developed requiring PATH to solve
a mixed complementarity problem. To overcome the necessity of maintaining
a different version of PATH for each interface, the code was reorganized us
ing object-oriented design techniques. At the same time, robustness issues
were considered and enhancements made to the algorithm. In this paper, we d
ocument the external interfaces to the PATH code and describe some of the n
ew utilities using PATH. We then discuss the enhancements made and compare
the results obtained from PATH 2.9 to the new version.