Insight into the depth and breadth of knowledge for use in and across disciplines is of vital importance. Our knowledge maps are visualizations based on empirical evidence about both collection characteristics and knowledge clusters such as disciplines. We report in this paper on collaborative efforts over several years, combining the resources of the Knowledge Space Lab and the Research and Innovation Group at DANS. In particular, we were interested in the narrative of how knowledge and knowledge systems change over time. Knowledge organization systems are evolving complex systems. Their analysis, both concerning inner structure, evolution over time, and their implementation in information spaces is important to better understand how knowledge is produced and can be navigated through.