The ECLiPSe Constraint Logic Programming System is designed for solving combinatorial optimization problems, for the development of new constraint solver technology and their hybrids, and for the teaching of modelling, solving and search techniques.
Proshee is a Prolog type-inference system written in Prolog but depending on the banshee project in C (banshee.sourceforge.net). At present it manages very simple type-inference, but it has some problems with lists that need to be overcome.