Mathematica 9 is now available
Technology Guide--The Technology Inside Matters
Constrained Nonlinear Optimization

Algorithms developed at Wolfram Research give Mathematica industrial-strength constrained nonlinear optimization and fitting. Mathematica provides a uniquely powerful modeling language in which problems can be specified directly in symbolic form--and then automatically analyzed to select the best algorithms to use.

Minimize over Arbitrary Regions Handle Systems of Nonlinear Constraints
Minimize over Arbitrary Regions Handle Systems of Nonlinear Constraints