The general algebraic modeling system (GAMS) is a high-level modeling system for mathematical optimization. GAMS is designed for modeling and solving linear, nonlinear, and mixed-integer optimization problems. The system is tailored for complex, large-scale modeling applications and allows the user to build large maintainable models that can be adapted to new situations. The system is available for use on various computer platforms. Models are portable from one platform to another. GAMS was the first algebraic modeling language (AML) and is formally similar to commonly used fourth-generation programming languages. GAMS contains an integrated development environment (IDE) and is connected to a group of third-party optimization solvers. Among these solvers are BARON, COIN-OR solvers, CONOPT, CPLEX, DICOPT, MOSEK, SNOPT, SULUM, and XPRESS. GAMS allows the users to implement a sort of hybrid algorithm combining different solvers. Models are described in concise, human-readable algebraic statements. GAMS is among the most popular input formats for the NEOS Server. Although initially designed for applications related to economics and management science, it has a community of users from various backgrounds of engineering and science. Timeline 1976 GAMS idea is presented at the International Symposium on Mathematical Programming (ISMP), Budapest 1978 Phase I: GAMS supports linear programming. Supported platforms: Mainframes and Unix Workstations 1979 Phase II: GAMS supports nonlinear programming. 1987 GAMS becomes a commercial product 1988 First PC System (16 bit) 1988 Alex Meeraus, the initiator of GAMS and founder of GAMS Development Corporation, is awarded INFORMS Computing Society Prize 1990 32 bit Dos Extender 1990 GAMS moves to Georgetown, Washington, D.C. 1991 Mixed Integer Non-Linear Programs capability (DICOPT) 1994 GAMS supports mixed complementarity problems 1995 MPSGE language is added for CGE modeling 1996 European branch opens in Germany 1998 32 bit native Windows 1998 Stochastic programming capability (OSL/SE, DECIS) 1999 Introduction of the GAMS Integrated development environment (IDE) 2000 End of support for DOS & Win 3.11 2000 GAMS World initiative started 2001 GAMS Data Exchange (GDX) is introduced 2002 GAMS is listed in OR/MS 50th Anniversary list of milestones 2003 Conic programming is added 2003 Global optimization in GAMS 2004 Quality assurance initiative starts 2004 Support for Quadratic Constrained programs 2005 Support for 64 bit PC Operating systems (Mac PowerPC / Linux / Win) 2006 GAMS supports parallel grid computing 2007 GAMS supports open-source solvers from COIN-OR 2007 Support for Solaris on Sparc64 2008 Support for 32 and 64 bit Mac OS X 2009