StumbleUpon is not a search engine or an internet directory. It´s an intelligent, personalized browsing tool which matches your interests with the collective recommendations of other users so that you may find the best and most relevant sites the web has to offer.

StumbleUpon uses member ratings to form collective human opinions on web site quality. Clicking the ´Stumble!´ button shows you high quality sites recommended by web surfers who share your interests.