In an increasingly technological world, the Internet is often the primary source of information. Traditional encyclopedias, once the cornerstone of any worthy reference collection, have been replaced by online encyclopedias, many of which utilize open source software (OSS) to create and update content. One of the most popular and successful encyclopedias of this nature is Wikipedia. In fact, Wikipedia is among the most popular Internet sites in the world. However, it is not without criticism. What are some features of Wikipedia? What are some of its strengths and weaknesses? And what have other wiki-based encyclopedias learned from Wikipedia that they have incorporated into their own Web sites in a quest for excellence? This paper answers these questions and uses Crawford's six information quality dimensions, (1) scope; (2) format; (3) uniqueness and authority; (4) accuracy; (5) currency; and (6) accessibility, to evaluate Wikipedia and three other online encyclopedias: Citizendium, Scholarpedia, and Medpedia. The latter three have managed to maintain the advantages of Wikipedia while minimizing its weaknesses.