MOPTA 2005
Interior Point OPTimizer (IPOPT)
¡An interior point algorithm for nonlinear, non-convex, constrained optimization problems
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l    Opened by CMU
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¡Andreas Waechter, Project Manager
lCarl Laird, C++ version
Differentiators
POOPT is the only interior-point-nlp-solver that’s both open-source and “good”.
Loco and Knitro are good ip-nlp solvers but proprietary.
IPOPT is the only one  that uses a “globally convergent” filter algorithm. (Distinguishes it from Loco).
Pennon (Germany) is another interior point solver – they solve *more* general problems but at this point performance lower on IPOPT’s class of problem .

Users from http://www.coin-or.org/Ipopt/  (see site for links to users)
Currently, IPOPT is/has been used in the following projects/products:
1. Other COIN-OR projects: NLPAPI and DFO
2.  Several research projects in Larry Biegler's group at CMU, including one with Ipopt as optimization engine in the process simulator ROMeoTM (slides)
3. In the IBM-internal circuit tuning tool EinsTuner
4. In ABB's Pulp and Paper Online Production Optimizer
5. Tobias Jockenhövel's OptControlCentre
6. By Ned Nedialkov in the context of solving Differential-Algebraic Equations
7. At the Munich University of Applied Sciences (for the course on "Modeling, Simulation and Optimization" by Dieter Kraft)
8. By Juan Arrieta, in the computation of optimal trajectories for spacecraft and related astronautics problems