GoRRiLA is a tool for randomly generating (i) linear arithmetic problems
and (ii) propositional problems and evaluating solvers on them.
There are a number of parameters which allow
to generate small and at the same time hard random problems.
GoRRiLA is a free software distributed under The GNU General Public License.
GoRRiLA at Google Code.
Examples of some interesting generated problems for linear integer arithmetic
with the number of variables 2-4:
problems_lia_2_4.tar.gz and linear rational arithmetic with 30 variables:
See also Hard Reality Tool for randomly extracting
hard and realistic theory problems (conjunctive constraints) from SMT problems with a non-trivial boolean structure.
Old version of GoRRiLA can be downloaded here:
linux binary (64bit)