Social software is a new paradigm that is spreading quickly in society, organizations and economics. It supports social interaction and social production. Social interaction is the interaction of non-predetermined individuals. Social production is the creation of artifacts, by combining the input from independent contributors without predetermining the way to do this [1]. Users are supported in creating new contacts, presenting themselves and collaborating with other users. As a result, content, knowledge and software is not created by a hierarchy of experts, but by combining a multitude of contributions of independent authors/actors. Examples for such a social production are wikis, blogs, social bookmarking and tagging, etc.