Why would Stonhenge have more credibility than Brainbench? The latter seems to be a legitimate company, whose focus happens to be certification. If you mean because more people in the Perl community have heard of Stonehenge than Brainbench, you miss the point of certifications: being able to demonstrate your technical ability to non-technical people, via a standardized objective, third-party test. Not trying to knock either company (I happen to think pretty highly of them both), just pointing out that one having more "credibility" than the other is a silly statement.