Agile methodologies have recently gained growing success in many economic and technical spheres. This is due to the fact that flexibility, in particular fast and efficient reactions to changed prerequisites, is becoming increasingly important in the information society. To support adaptive, semantic collaboration between domain experts and knowledge engineers, a new, agile knowledge engineering methodology, called RapidOWL is proposed. This methodology is based on the idea of iterative refinement, annotation and structuring of a knowledge base. A central paradigm for the RapidOWL methodology is the concentration on smallest possible information chunks. The collaborative aspect comes into play, when those information chunks can be selectively added, removed, annotated with comments or ratings. Design rationales for the RapidOWL methodology are to be light-weight, easy-to-implement, and support of spatially distributed and highly collaborative scenarios.