Don't get the idea that CLP can perform magic. You need a great deal of experience before you can choose the correct algorithms and correct expression of the constraints to get a good solution for big problems. Nevertheless, the interactive nature and highly expressive power of CLP languages makes it easy to experiment with different combinations. This results in much shorter and more maintainable programs than when using a procedural language. The founding work on the CLP scheme was done at Monash University in Melbourne, Australia, by J. Jaffar and J. L. Lassez around 1987.
CHIP provides constraint solvers over finite arithmetic, linear rational, and Boolean domains.
Eclipse also employs the powerful generalized propagation technique, and a parallel version of Eclipse is currently under development.