Allpairs

Lets say you must test something that involves a lot of different variables. Configuration testing is like that: different printers, different print options, different documents. Who knows what combination will fail?
But you cant try all combinations of all variables together, because that would be too many tests. So instead, you could create tests that pair each value of each of the variables with each value of each other variable at least once.
The Allpairs application was developed to be a small tool that finds a reasonably small set of test cases to satisfy that coverage standard. For instance, to try all combinations of 10 variables with ten values each would require 10,000,000,000 test cases. Allpairs only requires 177 cases. Allpairs is a command-line executable based on a Perl script. Source is included.