“As of October, 1999, about 200 million people regularly access the Internet. However, this access is still more or less standardized in that almost everyone uses the same means of information retrieval. It is unlikely that 200 million people are so similar in their interests that one standardized way of retrieving information fits all needs. This paper takes a look at about 50 available personalization systems, proposes a classification scheme and discusses the systems w.r.t. to this classification.” (Alexander Pretschner and Susan Gauch)