Research in evolution goes on par with the use of versioning systems by developers of the case studies. There is a great diversity of versioning systems with advantages and disadvantages both from the technical as well as from the conceptual point of view. In this paper we analyze the currently used versioning systems from the point of view of a software evolution researcher. Thus we do not focus on whether a certain versioning system is technically better than another one, but rather on what kind of information it offers for software evolution research. We present a non-exhaustive list of dimensions that are important for performing research in software evolution, do a survey on the current main-stream versioning systems and discuss what is actually needed for future versioning systems to support both software evolution and the related research field.