killMS implements two very efficient algorithms for solving the Direction-Dependent calibration problem (also known as third generation calibration). This problem naturally arises in the Radio Interferometry Measurement Equation (RIME), but only became overwhelmingly problematic with the construction of the SKA precursors and pathfinders. Solving for the DDE calibration problem basically consists in inverting a number of non-linear equations, while the system is very large and often subject to ill conditioning. The two algorithms killMS uses are based on complex optimization techniques and exploit algorithmic shortcuts; killMS also runs an extended Kalman filter.