Even though Wikis have made their way into software engineering practice, the number of empirical evaluations is not significant enough yet to make a statement on which software engineering phases wikis should be used for. This is also due to facts that wikis and related Web technologies are evolving fast and that a lot of effort is spent on developing new, innovative wiki-based solutions for specific software engineering activities. Therefore, two case studies were conducted in which wikis were used as a technology for communication, documentation, and knowledge sharing. Based on the subjective judgments of undergraduate and graduate students, wikis were evaluated as most efficient for sharing software engineering experiences and project management related information. In addition, both case studies shed light on the kind of information that was shared most and on its quality for reuse. The findings helped us to enhance the so-called wiki-based Software Organization Platform.