The following randomly generated constraint satisfaction problem instances I have used in some of my publications:

• Model B, 15 variables, domainsize 15
• Model E, 15 variables, domainsize 15
• Model E, 20 variables, domainsize 20
• Model F, 20 variables, domainsize 20

The test set of randomly generated constraint satisfaction problem instances used in my PhD-thesis can be downloaded here.

The following projects have their own pages:

• JavaCsp: a constraint satisfaction problem generator developed with lots of extra features such as a set of solvers;
• JavaEa2: an experimental platform developed for researching evolutionary algorithms for solving constraint satisfaction problems; and
• RepositoryCsp: a collection of generated random constraint satisfaction problems for use with JavaCsp and JavaEa2.