See <en.wikipedia.org/wiki/List_of_lists_of_mathematical_topics>. Recently it was stated in this newsgroup that anyone can post anything they want there. I think that is misleading. When you edit one of these pages, people are watching. If you insert an obscenity, it will probably be deleted within minutes. If you delete all of the content of an article, ditto. If you put in a misspelling, it may take longer. If you put an erronenous mathematical assertion, it may not take long. Hundreds of mathematicians have worked on Wikipedia. If you edit an article that a logged-in user has put on his watchlist (logged-in users can do that), then he will know what you did the next time he clicks on "my watchlist". If you click on "history" or "page history" you will see who has contributed what to the article, on what dates (and times, to the minute). The result, as far as math articles go, is that (1) articles on topics that only mathematicians are likely to know about are often quite good; (2) articles on topics such as calculus that zillions of students take are sometimes clumsily written, but even there, those who edit are usually eager to learn from those who know more -- otherwise they wouldn't be there. And sometimes people get banned for not behaving themselves. The URL above says "list of lists of ...", not just "list of..." That page is a remarkable table of contents of mathematics. Some of the lists contain perhaps a couple of hundred math articles; some have only a couple of dozen or so. -- Mike Hardy