We picked four of the top programs for this review. There are other programs out there but these are the biggest and best known. The criteria we used was based on which was the most accurate, the easiest to use, the best features, and price mattered too.
The software must be accurate. If it misses obvious errors then it is not useful.
We wanted software that was easy and fast. If it could not be used quickly, then it is unlikely that anyone would use it as often as they should.
We also wanted software that did more than hi light errors. It had to make suggestions and name the actual problem. Just hi lighting a problem area and saying there was a problem was not acceptable.
That is a fairly short list of needs. Accurate and easy to use. With this checklist in hand we started testing.