GAMS
"The General Algebraic Modeling System (GAMS) is a high-level
modeling system for mathematical programming problems. It consists of
a language compiler and a stable of integrated high-performance
solvers. GAMS is tailored for complex, large scale modeling
applications, and allows you build large maintainable models that can
be adapted quickly to new situations." It can run on machines that vary
in size from PC to supercomputers.
At this site you can read about GAMS, including solvers and
supported platforms. They also offer extensive documentation
(including FAQs and an index to their model library), information
on contributed software, and material on workshops and courses.
Information: gams@gams.com http://www.gams.com/