Goals: - Answers should not be obvious: - Keywords shouldn't give away the answer, e.g. unittest { ... } is obviously an unit test block. - return 2+2 is obvious to non-programmers. - Answers should vary considerably: - A question which has the answer "0" much of the time is easy to defeat simply by giving the answer "0" all of the time. - Questions should not be Google-able: - Search engines ignore most punctuation and math operators. - Keywords and string literals should vary or be generic enough.
A CAPTCHA generator for D services. Written in the D programming language.