-->Cacao (Constraint Library in C++)
a. http://sourceforge.net/projects/cacao
--> C and C++ Constraint Library
a. http://www.hulubei.net/tudor/csp/
--> Choco (JAVA )
a. http://choco.sourceforge.net
-->Chorus3D: A geometric constraint library for 3D graphical applications
a. No working website to download but you can refer to the documentation at the following website http://delivery.acm.org/10.1145/570000/569019/p94-hosobe.pdf?key1=569019&key2=1466433511&coll=GUIDE&dl=ACM&CFID=15151515&CFTOKEN=6184618
--> Clixml (A schema validator for the CLiXML (Constraint Language in XML) schema constraint language.)
a. http://sourceforge.net/projects/clixml
b. OS Independent (Written in an interpreted language)
c. Availability: Free
--> 'C' library of routines for solving binary constraint satisfaction problems
a. http://ai.uwaterloo.ca/~vanbeek/software/software.html
--> 'C' library for constraint satisfaction problems – Peter van Beek
a. http://ai.uwaterloo.ca/~vanbeek/software/software.html
--> Distributed Constraint Solver (C++)
a. http://research.microsoft.com/~youssefh/DisolverWeb/Disolver.html
-->ECLiPSE (Prolog)
a. http://www.cs.jhu.edu/~jason/425/eclipse-doc/libman/libman.html
-->EFC: C++ based constraint library
a. No working website to download but you can refer to the documentation at the following website. http://www.cs.toronto.edu/~gkatsi/efc/README
--> Elisa: C++ library implementing generic constraint algorithms
a. http://www.recherche.enac.fr/opti/facile/
b. All POSIX (Linux/BSD/UNIX-like OSes) , Linux, Free
--> FaCiLe: A Functional Constraint Library (C++)
a. http://www.recherche.enac.fr/opti/facile/
b. Any operating system , free
-->Finite Element LibrarY eXperiment: C++ library that provides the most common elements for structural analysis, bandwidth reduction, a fast skyline solver, some iterative solvers and an interface to the commercial FEA package ANSYS.
a. http://sourceforge.net/projects/felyx
--> ILOG J-Solver: (JAVA)
a. http://www.ilog.com/products/jsolver/
--> Java Constraints library
--> Mecado (PHP) library provides an easy way to access database with XML mapping
a. http://sourceforge.net/projects/mecado
-->OTI Constraint Solver
-->The pwan OCL library (C++) - implementation of the UML's Object Constraint Language.
a. http://sourceforge.net/projects/pwan
-->Screamer (LISP)
a. http://www.cis.upenn.edu/~screamer-tools/home.html
--> Sicstus (PROLOG)
a. http://www.sics.se/isl/sicstuswww/site/index.html
--> YACS – Yet another constraint solver (JAVA)
a. http://sourceforge.net/projects/constraints