CPLEX Optimization, Inc. was founded in 1988 with the mission of providing the highest-performance optimizers for linear programming. CPLEX was the first commercial linear programming optimizer developed in the "C" programming language. The first CPLEX products were CPLEX Linear Optimizer and CPLEX Callable Library.

The name "CPLEX" comes from the combination of the letter "C" for the programming language, and the word "simplex" for the simplex method for linear programming.

Milestones
Significant milestones in the history of CPLEX include:

• 2008
  ILOG CPLEX turns 20! CPLEX established an immediate LP leadership role with its very first release, and two decades later it remains recognized as the performance and marketplace leader in LP/MIP.

• October, 2007
  ILOG CPLEX 11.0 is released, with breakthrough performance gains for mixed integer programming (MIP) models and enhanced parallel MIP optimization. The MIP solution pool feature and the performance tuning utility are introduced.

• January, 2006
  ILOG CPLEX 10.0 is released, with performance improvements in the primal simplex and barrier methods, as well as the MIP optimizer. Indicator constraints and solution polishing heuristics are introduced and improvements to infeasibility analysis are made.

• October, 2004
  The first Institute for Operations Research and the Management Sciences (INFORMS) IMPACT prize is awarded for the creation and widespread dissemination of ILOG CPLEX.

• December, 2003
  ILOG CPLEX 9.0 is released, with performance improvements in primal and dual simplex methods and the MIP optimizer. It includes ILOG Concert Technology for .NET users and support for quadratically constrained programs.

• July, 2002
  ILOG CPLEX 8.0 is released, with MIP performance improvements and support for mixed integer quadratic programs.

• December, 2001
  ILOG CPLEX 7.5 is released, including ILOG Concert Technology for Java users.

• October, 2000
  ILOG CPLEX 7.0 is released, including ILOG Concert Technology for C++ users.

• March, 1999
  ILOG CPLEX 6.5 is released, with significant performance improvements in primal and dual simplex methods, and ILOG CPLEX Mixed Integer Optimizer.

• April, 1998
  ILOG CPLEX 6.0 is released, with significant performance improvements in primal and dual simplex methods, and CPLEX Barrier Optimizer.

• September, 1997
  ILOG CPLEX 5.0 is released, with a new memory model for easy C++ integration.

• August, 1997
  ILOG acquires CPLEX Optimization, Inc.

• March, 1996
  Parallel CPLEX Mixed Integer Solver is introduced.

• December, 1995
  CPLEX 4.0 is released, with a redesigned advanced programming interface (API) to allow thread-safe applications.

• March, 1995
  Parallel CPLEX Barrier Solver is introduced.

• April, 1994
  CPLEX 3.0 is released, including CPLEX Barrier Solver.

• March, 1993
  CPLEX 2.1 is released, including CPLEX presolve algorithms.

• April, 1992
  CPLEX 2.0 is released.

• 1991
  CPLEX 1.2 is released, with support for the dual simplex method and CPLEX Mixed Integer Optimizer.

• 1988
  CPLEX 1.0 is released, with support for the primal simplex method.

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