ILOG CPLEX (often informally referred to simply as CPLEX) is an optimization software package. It is named for the simplex method and the C programming language, although today it contains interior point methods and interfaces in the C++ , C Sharp, and Java languages. It was originally developed by Robert E. Bixby and sold via CPLEX Optimization Inc., which was acquired by ILOG in 1997. CPLEX solves integer programming problems, very large linear programming problems, quadratic programming problems, and has recently added support for problems with convex quadratic constraints (solved via Second-order cone programming, or SOCP). It has a modeling layer called Concert and is also available with several modeling systems like AIMMS, AMPL, GAMS, MPL, OPL Development Studio, and TOMLAB.