Purity tests have existed for ages, originally taking the form of written lists of questions. With the advent of the Net, it became popular to distribute them by electronic means. Some were modified to be programs or shell scripts which would ask you each question in turn, and do the calculations for you when you were done. In 1989, Eric Lechner wrote a program that would do the same thing using data files that described different purity tests. He converted various purity tests to this format and made the package available. By 1995, when I first posted these links, purity tests could be found online, where they'd calculate the scores for you. Too fun! Enjoy!